Electronic apparatus, system, determination method, determination program, and recording medium

ABSTRACT

An electronic apparatus includes a determination section that performs a determination of a standing still state of exercise equipment on the basis of a preset determination criterion by using an output from an inertial sensor, and a notification section that notifies a user of information indicating a state change of the exercise equipment until reaching the determination.

BACKGROUND 1. Technical Field

The present invention relates to an electronic apparatus, a system, adetermination method, a determination program, and a recording medium.

2. Related Art

JP-A-2014-100341 discloses a terminal apparatus which detects anattitude in a standing still state by using a motion sensor, and theninstructs a user to start a swing from a display section or a speaker.If the user performs a swing on the basis of the instruction from theterminal apparatus, impact is detected through ball hitting, and swinganalysis is performed by the terminal apparatus.

However, there is a case where the user takes an address attitude andstands still, but the terminal apparatus does not give an instructionfor swing starting. As causes thereof, there may be the following cause(1) or cause (2).

The cause (1) is a case where the terminal apparatus or the motionsensor fails.

The cause (2) is a case where, even if the user stands still at anaccurate attitude, the exercise equipment does not satisfy a conditionfor being determined as standing still by the terminal apparatus.

Of the causes, in a case of the cause (1), the terminal apparatus or themotion sensor is required to be repaired, but, in a case of the cause(2), the terminal apparatus or the motion sensor is not necessarily tobe repaired, and the user has only to adjust the address attitude.

However, it is difficult for the user to determine which one of thecauses (1) and (2) is a real cause. Thus, a problem may occur in thatthe user requests a manufacturer of the terminal apparatus or the motionsensor to repair the terminal apparatus or the motion sensor despite acause being the cause (2), or the user spends time in trying to improvean address attitude many times despite a cause being the cause (1).

SUMMARY

An advantage of some aspects of the invention is to provide anelectronic apparatus, a system, a determination method, a determinationprogram, and a recording medium, capable of assisting a user incomfortably using a function of determining a state of exerciseequipment.

The invention can be implemented as the following aspects or applicationexamples.

APPLICATION EXAMPLE 1

An electronic apparatus according to this application example includes adetermination section that performs a determination of a standing stillstate of an exercise equipment on the basis of a preset determinationcriterion by using an output from an inertial sensor; and a notificationsection that notifies a user of information indicating a state change ofthe exercise equipment until reaching the determination.

According to the electronic apparatus of this application example, sincea user is notified of a state change of the exercise equipment untilreaching the determination, the user can compare a state change of theexercise equipment in a case where a preset determination criterion isnot satisfied with a state change of the exercise equipment in a casewhere the preset determination criterion is satisfied.

APPLICATION EXAMPLE 2

In the application example, the notification section may notify the userof permission of starting of a swing of the exercise equipment in a casewhere the exercise equipment is maintained in a predetermined state fora predetermined period of time.

Therefore, in the electronic apparatus of the application example, auser can obtain permission of motion starting from the electronicapparatus by taking a predetermined pose (for example, an attitude suchas an address attitude in golf) before starting the motion.

APPLICATION EXAMPLE 3

In the application example, the notification section may notify the userof information indicating an attitude change of the exercise equipment.

Therefore, according to the electronic apparatus of the applicationexample, since a user is notified of an attitude change of the exerciseequipment until reaching the determination, the user can compare anattitude change of the exercise equipment in a case where a presetdetermination criterion is not satisfied with an attitude change of theexercise equipment in a case where the preset determination criterion issatisfied.

APPLICATION EXAMPLE 4

In the application example, the exercise equipment may be a golf club,and the notification section may notify the user of an attitude changeof the golf club in a direction intersecting a ground plane as theinformation.

Through the notification, the user can understand the extent of beingunstable in a vertical direction (a vertical direction of the userdirecting a visual line toward a head) of the hands holding the golfclub.

APPLICATION EXAMPLE 5

In the application example, the exercise equipment may be a golf club,and the notification section may notify the user of an attitude changeof the golf club in a horizontal direction with respect to a groundplane as the information.

Through the notification, the user can understand the extent of beingunstable in a horizontal direction (a horizontal direction of the userdirecting a visual line toward a head) of the hands holding the golfclub.

APPLICATION EXAMPLE 6

In the application example, the exercise equipment may be a golf club,and a criterion of the determination may be set on the basis of a lieangle of the golf club.

Therefore, the electronic apparatus causes the user to take an attitudeappropriate for a lie angle of the golf club by using this determinationcriterion.

APPLICATION EXAMPLE 7

In the application example, the notification section may notify the userof the criterion of the determination along with the information.

Therefore, the user can check a relationship between a state change ofthe exercise equipment and the determination criterion during adetermination.

APPLICATION EXAMPLE 8

In the application example, the notification section may perform thenotification by using at least one of an image, light, sound, vibration,an image change pattern, a light change pattern, a sound change pattern,and a vibration change pattern.

Therefore, the user can recognize a state change of the exerciseequipment with at least one of a visual sense, a tactile sense, and anauditory sense.

APPLICATION EXAMPLE 9

In the application example, the inertial sensor may include at least oneof an acceleration sensor and an angular velocity sensor.

Therefore, the electronic apparatus can determine a state (for example,at least one of an acceleration, a velocity, a position, an attitudechange, and an attitude) of the exercise equipment.

APPLICATION EXAMPLE 10

A system according to this application example includes any one of theelectronic apparatuses according to the application examples; and theinertial sensor.

APPLICATION EXAMPLE 11

A system according to this application example includes any one of theelectronic apparatuses according to the application examples; and a headmounted display that displays the information.

APPLICATION EXAMPLE 12

A system according to this application example includes any one of theelectronic apparatuses according to the application examples; and an armmounted display that displays the information.

APPLICATION EXAMPLE 13

A determination method according to this application example includesperforming a determination of a standing still state of exerciseequipment on the basis of a preset determination criterion by using anoutput from an inertial sensor; and notifying a user of informationindicating a state change of the exercise equipment until reaching thedetermination.

APPLICATION EXAMPLE 14

In the determination method of the application example, in the notifyingof the information, the user may be notified of permission of startingof a swing of the exercise equipment in a case where the exerciseequipment is maintained in a predetermined state for a predeterminedperiod of time.

APPLICATION EXAMPLE 15

In the determination method of the application example, in the notifyingof the information, the user may be notified of information indicatingan attitude change of the exercise equipment.

APPLICATION EXAMPLE 16

In the determination method of the application example, the exerciseequipment may be a golf club, and, in the notifying of the information,the user may be notified of an attitude change of the golf club in adirection intersecting a ground plane as the information.

APPLICATION EXAMPLE 17

In the determination method of the application example, the exerciseequipment may be a golf club, and, in the notifying of the information,the user may be notified of an attitude change of the golf club in ahorizontal direction with respect to a ground plane as the information.

APPLICATION EXAMPLE 18

In the determination method of the application example, the exerciseequipment may be a golf club, and a criterion of the determination maybe set on the basis of a lie angle specific to the golf club.

APPLICATION EXAMPLE 19

In the determination method of the application example, in the notifyingof the information, the user may be notified of the criterion of thedetermination along with the information.

APPLICATION EXAMPLE 20

In the determination method of the application example, in the notifyingof the information, the notification maybe performed by using at leastone of an image, light, sound, vibration, an image change pattern, alight change pattern, a sound change pattern, and a vibration changepattern.

APPLICATION EXAMPLE 21

In the determination method of the application example, the inertialsensor may include at least one of an acceleration sensor and an angularvelocity sensor.

APPLICATION EXAMPLE 22

A determination program according to this application example causes acomputer to execute performing a determination of a standing still stateof exercise equipment on the basis of a preset determination criterionby using an output from an inertial sensor; and notifying a user ofinformation indicating a state change of the exercise equipment untilreaching the determination.

APPLICATION EXAMPLE 23

A recording medium according to this application example records adetermination program causing a computer to execute performing adetermination of a standing still state of an exercise equipment on thebasis of a preset determination criterion by using an output from aninertial sensor; and notifying a user of information indicating a statechange of the exercise equipment until reaching the determination.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a diagram illustrating a configuration example of a swinganalysis system of the present embodiment.

FIG. 2 is a diagram illustrating an example in which a sensor unit isattached.

FIG. 3 is a diagram illustrating examples of a position at which and adirection in which the sensor unit is attached.

FIG. 4 is a diagram illustrating procedures of actions performed by auser until the user hits a ball.

FIG. 5 is a diagram illustrating an example of an input screen ofphysical information and golf club information.

FIG. 6 is a diagram illustrating a swing action.

FIG. 7 is a diagram illustrating an example of a selection screen ofswing analysis data.

FIG. 8 is a diagram illustrating an example of a display screen.

FIG. 9 is a diagram illustrating configuration examples of the sensorunit and a swing analysis apparatus.

FIG. 10 is a plan view in which a golf club and the sensor unit areviewed from a negative side of an X axis during standing still of theuser.

FIG. 11 is a graph illustrating examples of temporal changes ofthree-axis angular velocities.

FIG. 12 is a graph illustrating a temporal change of a combined value ofthe three-axis angular velocities.

FIG. 13 is a graph illustrating a temporal change of a derivative of thecombined value.

FIG. 14 is a diagram illustrating a shaft plane and a Hogan plane.

FIG. 15 is a view in which a sectional view of the shaft plane which iscut in a YZ plane is viewed from the negative side of the X axis.

FIG. 16 is a view in which a sectional view of the Hogan plane which iscut in the YZ plane is viewed from the negative side of the X axis.

FIG. 17 is a diagram for explaining a face angle and a club path(incidence angle).

FIG. 18 is a diagram illustrating an example of a temporal change of ashaft axis rotation angle from swing starting (backswing starting) toimpact.

FIG. 19 is a diagram illustrating an example of a temporal change of aspeed of a grip in a downswing.

FIG. 20 is a diagram illustrating examples of relationships among theshaft plane and the Hogan plane, and a plurality of regions A, B, C, Dand E.

FIG. 21 is a flowchart illustrating examples of procedures of a swinganalysis process (swing analysis method).

FIG. 22 is a diagram illustrating a configuration example of a serverapparatus.

FIG. 23 is a flowchart illustrating examples of procedures of a processperformed by a swing analysis apparatus in relation to the serverapparatus.

FIG. 24 is a flowchart illustrating examples of procedures of a processperformed by the server apparatus.

FIG. 25 is a diagram illustrating an example of an indicator screen.

FIG. 26 is a diagram illustrating another example of an indicatorscreen.

FIG. 27 is a diagram illustrating still another example of an indicatorscreen.

FIG. 28 is a diagram illustrating still another example of an indicatorscreen.

FIG. 29 is a flowchart illustrating examples of procedures of a swinganalysis process (swing analysis method) (in which step S16 regarding adetermination of standing still is subdivided into a plurality of stepsS161 to S166 in a flow illustrated in FIG. 21).

FIG. 30 is a diagram illustrating an example of a wrist type displaysection.

FIG. 31 is a diagram illustrating an example of a head mounted display.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, preferred embodiments of the invention will be describedwith reference to the drawings. The embodiments described below are notintended to improperly limit the content of the invention disclosed inthe appended claims. In addition, all constituent elements describedbelow are not essential constituent elements of the invention.

Hereinafter, a swing analysis system analyzing a golf swing will bedescribed as an example in a case where exercise equipment is a golfclub.

1. SWING ANALYSIS SYSTEM 1-1. Configuration of Swing Analysis System

FIG. 1 is a diagram illustrating a configuration example of a swinganalysis system of the present embodiment. As illustrated in FIG. 1, aswing analysis system 1 of the present embodiment is configured toinclude a sensor unit 10, a swing analysis apparatus 20, and a serverapparatus 30.

The sensor unit 10 (an example of an inertial sensor) can measureacceleration generated in each axial direction of three axes and angularvelocity generated around each of the three axes, and is attached to agolf club 3 as illustrated in FIG. 2.

In the present embodiment, as illustrated in FIG. 3, the sensor unit 10is attached to a part of a shaft so that one axis of three detectionaxes (an x axis, a y axis, and a z axis), for example, the y axismatches a longitudinal direction of the shaft of the golf club 3 (alongitudinal direction of the golf club 3; hereinafter, referred to as alongitudinal direction). Preferably, the sensor unit 10 is attached to aposition close to a grip to which impact during ball hitting is hardlyforwarded and a centrifugal force is not applied during a swing. Theshaft is a shaft portion other than a head of the golf club 3 and alsoincludes the grip. However, the sensor unit 10 may be attached to a part(for example, the hand or a glove) of a user 2, and may be attached toan accessory such as a wristwatch.

The user 2 performs a swing action for hitting a golf ball 4 accordingto predefined procedures. FIG. 4 is a diagram illustrating procedures ofactions performed by the user 2 until the user hits the ball in thepresent embodiment. As illustrated in FIG. 4, first, the user 2 performsan input operation of physical information of the user 2, information(golf club information) regarding the golf club 3 used by the user 2,and the like via the swing analysis apparatus 20 (step S1). The physicalinformation includes at least one of information regarding a height, alength of the arms, and a length of the legs of the user 2, and mayfurther include information regarding sex or other information. The golfclub information includes at least one of information regarding a length(club length) of the golf club 3 and the type (number) of golf club 3.Next, the user 2 performs a measurement starting operation (an operationfor starting measurement in the sensor unit 10) via the swing analysisapparatus 20 (step S2). Next, after receiving a notification (forexample, a notification using a voice) of giving an instruction fortaking an address attitude (a basic attitude before starting a swing)from the swing analysis apparatus 20 (Y in step S3), the user 2 takes anaddress attitude so that the axis in the longitudinal direction of theshaft of the golf club 3 is perpendicular to a target line (target hitball direction), and stands still (step S4). Next, the user 2 receives anotification (for example, a notification using a voice) of permitting aswing from the swing analysis apparatus 20 (Y in step S5), and then hitsthe golf ball 4 by performing a swing action (step S6)

FIG. 5 is a diagram illustrating an example of an input screen ofphysical information and golf club information, displayed on a displaysection 25 (refer to FIG. 9) of the swing analysis apparatus 20. In stepS1 in FIG. 4, the user 2 inputs physical information such as a height,sex, age, and country, and inputs golf club information such as a clublength (a length of the shaft), and a club number on the input screenillustrated in FIG. 5. Information included in the physical informationis not limited thereto, and, the physical information may include, forexample, at least one of information regarding a length of the arms anda length of the legs instead of or along with the height. Similarly,information included in the golf club information is not limitedthereto, and, for example, the golf club information may not include atleast one of information regarding the club length and the club number,and may include other information.

If the user 2 performs the measurement starting operation in step S2 inFIG. 4, the swing analysis apparatus 20 transmits a measurement startingcommand to the sensor unit 10, and the sensor unit 10 receives themeasurement starting command and starts measurement of three-axisaccelerations and three-axis angular velocities. The sensor unit 10measures three-axis accelerations and three-axis angular velocities in apredetermined cycle (for example, 1 ms), and sequentially transmits themeasured data to the swing analysis apparatus 20. Communication betweenthe sensor unit 10 and the swing analysis apparatus 20 may be wirelesscommunication, and may be wired communication.

The swing analysis apparatus 20 notifies the user 2 of permission ofswing starting, shown in step S5 in FIG. 4, and then analyzes the swingaction (step S6 in FIG. 4) in which the user 2 has hit the ball by usingthe golf club 3 on the basis of measured data from the sensor unit 10.

As illustrated in FIG. 6, the swing action performed by the user 2 instep S6 in FIG. 4 includes an action reaching impact (ball hitting) atwhich the golf ball 4 is hit through respective states of halfway backat which the shaft of the golf club 3 becomes horizontal during abackswing after starting a swing (backswing), a top at which the swingchanges from the backswing to a downswing, and halfway down at which theshaft of the golf club 3 becomes horizontal during the downswing. Theswing analysis apparatus 20 generates swing analysis data includinginformation regarding a time point (date and time) at which the swing isperformed, identification information or the sex of the user 2, the typeof golf club 3, and an analysis result of the swing action, andtransmits the swing analysis data to the server apparatus 30 via anetwork 40 (refer to FIG. 1).

The server apparatus 30 receives the swing analysis data transmitted bythe swing analysis apparatus 20 via the network 40, and preserves theswing analysis data. Therefore, when the user 2 performs a swing actionaccording to the procedures illustrated in FIG. 4, the swing analysisdata generated by the swing analysis apparatus 20 is preserved in theserver apparatus 30, and thus a swing analysis data list is built.

For example, the swing analysis apparatus 20 is implemented by aninformation terminal (client terminal) such as a smart phone or apersonal computer, and the server apparatus 30 is implemented by aserver which processes requests from the swing analysis apparatus 20.

The network 40 may be a wide area network (WAN) such as the Internet,and may be a local area network (LAN). Alternatively, the swing analysisapparatus 20 and the server apparatus 30 may communicate with each otherthrough, for example, near field communication or wired communication,without using the network 40.

In the present embodiment, if the user 2 activates a swing analysisapplication via an operation section 23 (refer to FIG. 9) of the swinganalysis apparatus 20, the swing analysis apparatus 20 performscommunication with the server apparatus 30, and, for example, aselection screen of swing analysis data as illustrated in FIG. 7 isdisplayed on the display section 25 of the swing analysis apparatus 20.The selection screen includes a time point (date and time), the type ofgolf club which has been used, and some index values as analysis resultsof a swing, with respect to each item of swing analysis data regardingthe user 2 included in the swing analysis data list preserved in theserver apparatus 30.

A checkbox correlated with each item of swing analysis data is locatedat a left end of the selection screen illustrated in FIG. 7, and theuser 2 checks any one of the checkboxes by operating the swing analysisapparatus 20, and then presses an OK button located on a lower part inthe selection screen. Consequently, the swing analysis apparatus 20performs communication with the server apparatus 30, and displays swinganalysis data correlated with the checked checkbox on the selectionscreen illustrated in FIG. 7, on the display section 25 of the swinganalysis apparatus 20 (for example, refer to FIG. 8).

1-2. Configurations of Sensor Unit and Swing Analysis Apparatus

FIG. 9 is a diagram illustrating configuration examples of the sensorunit 10 and the swing analysis apparatus 20. As illustrated in FIG. 9,in the present embodiment, the sensor unit 10 is configured to includean acceleration sensor 12, an angular velocity sensor 14, a signalprocessing section 16, and a communication section 18. However, thesensor unit 10 may have a configuration in which some of the constituentelements are deleted or changed as appropriate, or may have aconfiguration in which other constituent elements are added thereto.

The acceleration sensor 12 measures respective accelerations in threeaxial directions which intersect (ideally, orthogonal to) each other,and outputs digital signals (acceleration data) corresponding tomagnitudes and directions of the measured three-axis accelerations.

The angular velocity sensor 14 measures respective angular velocities inthree axial directions which intersect (ideally, orthogonal to) eachother, and outputs digital signals (angular velocity data) correspondingto magnitudes and directions of the measured three-axis angularvelocities.

The signal processing section 16 receives the acceleration data and theangular velocity data from the acceleration sensor 12 and the angularvelocity sensor 14, respectively, adds time information thereto, storesthe data in a storage portion (not illustrated), adds time informationto the stored measured data (acceleration data and angular velocitydata) so as to generate packet data conforming to a communicationformat, and outputs the packet data to the communication section 18.

Ideally, the acceleration sensor 12 and the angular velocity sensor 14are provided in the sensor unit 10 so that the three axes thereof matchthree axes (an x axis, a y axis, and a z axis) of an orthogonalcoordinate system (sensor coordinate system) defined for the sensor unit10, but, actually, errors occur in installation angles. Therefore, thesignal processing section 16 performs a process of converting theacceleration data and the angular velocity data into data in the XYZcoordinate system by using a correction parameter which is calculated inadvance according to the installation angle errors.

The signal processing section 16 may perform a process of correcting thetemperatures of the acceleration sensor 12 and the angular velocitysensor 14. Alternatively, the acceleration sensor 12 and the angularvelocity sensor 14 may have a temperature correction function.

The acceleration sensor 12 and the angular velocity sensor 14 may outputanalog signals, and, in this case, the signal processing section 16 mayA/D convert an output signal from the acceleration sensor 12 and anoutput signal from the angular velocity sensor 14 so as to generatemeasured data (acceleration data and angular velocity data), and maygenerate communication packet data by using the data.

The communication section 18 performs a process of transmitting packetdata received from the signal processing section 16 to the swinganalysis apparatus 20, or a process of receiving various controlcommands such as a measurement starting command from the swing analysisapparatus 20 and sending the control command to the signal processingsection 16. The signal processing section 16 performs various processescorresponding to control commands.

As illustrated in FIG. 9, in the present embodiment, the swing analysisapparatus 20 (an example of an electronic apparatus) is configured toinclude a processing section 21 (an example of a determination section),a communication section 22, an operation section 23, a storage section24, a display section 25 (an example of a notification section), a soundoutput section 26 (an example of a notification section), and acommunication section 27. However, the swing analysis apparatus 20 mayhave a configuration in which some of the constituent elements aredeleted or changed as appropriate, or may have a configuration in whichother constituent elements are added thereto.

The communication section 22 performs a process of receiving packet datatransmitted from the sensor unit 10 and sending the packet data to theprocessing section 21, or a process of transmitting a control commandfrom the processing section 21 to the sensor unit 10.

The operation section 23 performs a process of acquiring operation datafrom the user 2 and sending the operation data to the processing section21. The operation section 23 may be, for example, a touch panel typedisplay, a button, a key, or a microphone.

The storage section 24 is constituted of, for example, various ICmemories such as a read only memory (ROM), a flash ROM, and a randomaccess memory (RAM), or a recording medium such as a hard disk or amemory card. The storage section 24 stores a program (an example of adetermination program) for the processing section 21 performing variouscalculation processes or a control process, or various programs or datafor realizing application functions.

In the present embodiment, the storage section 24 stores a swinganalysis program 240 which is read by the processing section 21 andexecutes a swing analysis process. The swing analysis program 240 may bestored in a nonvolatile recording medium (computer readable recordingmedium) in advance, or the swing analysis program 240 may be receivedfrom a server (not illustrated) or the server apparatus 30 by theprocessing section 21 via a network, and may be stored in the storagesection 24.

In the present embodiment, the storage section 24 stores golf clubinformation 242, physical information 244, sensor attachment positioninformation 246, and swing analysis data 248. For example, the user 2may operate the operation section 23 so as to input specificationinformation regarding the golf club 3 to be used (for example, at leastsome information such as information regarding a length of the shaft, aposition of the centroid thereof, a lie angle, a face age, a loft angle,and the like) from the input screen illustrated in FIG. 5, and the inputspecification information may be used as the golf club information 242.Alternatively, in step S1 in FIG. 4, the user 2 may sequentially inputtype numbers of the golf club 3 (alternatively, selects a type numberfrom a type number list) so that specification information for each typenumber is stored in the storage section 24 in advance. In this case,specification information of an input type number may be used as thegolf club information 242.

For example, the user 2 may input physical information by operating theoperation section 23 from the input screen illustrated in FIG. 5, andthe input physical information may be used as the physical information244. For example, instep S1 in FIG. 4, the user 2 may input anattachment position of the sensor unit 10 and a distance to the grip endof the golf club 3 by operating the operation section 23, and the inputdistance information may be used as the sensor attachment positioninformation 246. Alternatively, the sensor unit 10 may be attached at adefined predetermined position (for example, a distance of 20 cm fromthe grip end), and thus information regarding the predetermined positionmay be stored as the sensor attachment position information 246 inadvance.

The swing analysis data 248 is data including information regarding aswing action analysis result in the processing section 21 (swinganalysis portion 211) along with a time point (date and time) at which aswing was performed, identification information or the sex of the user2, and the type of golf club 3.

The storage section 24 is used as a work area of the processing section21, and temporarily stores data which is input from the operationsection 23, results of calculation executed by the processing section 21according to various programs, and the like. The storage section 24 maystore data which is required to be preserved for a long period of timeamong data items generated through processing of the processing section21.

The display section 25 displays a processing result in the processingsection 21 as text, a graph, a table, animation, and other images. Thedisplay section 25 may be, for example, a CRT, an LCD, a touch paneltype display, and a head mounted display (HMD). A single touch paneltype display may realize functions of the operation section 23 and thedisplay section 25.

The sound output section 26 outputs a processing result in theprocessing section 21 as a sound such as a voice or a buzzer sound. Thesound output section 26 may be, for example, a speaker or a buzzer.

The communication section 27 performs data communication with acommunication section 32 (refer to FIG. 22) of the server apparatus 30via the network 40. For example, the communication section 27 performs aprocess of receiving the swing analysis data 248 from the processingsection 21 after a swing analysis process is completed, and transmittingthe swing analysis data to the communication section 32 of the serverapparatus 30. For example, the communication section 27 performs aprocess of receiving information required to display the selectionscreen illustrated in FIG. 7 from the communication section 32 of theserver apparatus 30 and transmitting the information to the processingsection 21, and a process of receiving selected information on theselection screen illustrated in FIG. 7 from the processing section 21and transmitting the selected information to the communication section32 of the server apparatus 30. For example, the communication section 27performs a process of receiving information required to display thedisplay screen illustrated in FIG. 8 from the communication section 32of the server apparatus 30, and transmitting the information to theprocessing section 21.

The processing section 21 performs a process of transmitting a controlcommand to the sensor unit 10 via the communication section 22, orvarious computation processes on data which is received from the sensorunit 10 via the communication section 22, according to various programs.The processing section 21 performs a process of reading the swinganalysis data 248 from the storage section 24, and transmitting theswing analysis data to the server apparatus 30 via the communicationsection 27, according to various programs. The processing section 21performs a process of transmitting various pieces of information to theserver apparatus 30 via the communication section 27, and displayingvarious screens (the respective screens illustrated in FIGS. 7 and 8) onthe basis of the information received from the server apparatus 30,according to various programs. The processing section 21 performs othervarious control processes.

Particularly, in the present embodiment, by executing the swing analysisprogram 240, the processing section 21 functions as a data acquisitionportion 210, a swing analysis portion 211, an image data generationportion 212, a storage processing portion 213, a display processingportion 214, and a sound output processing portion 215, and performs aprocess (swing analysis process) of analyzing a swing action of the user2.

The data acquisition portion 210 performs a process of receiving packetdata which is received from the sensor unit 10 by the communicationsection 22, acquiring time information and measured data in the sensorunit 10 from the received packet data, and sending the time informationand the measured data to the storage processing portion 213. The dataacquisition portion 210 performs a process of receiving the informationrequired to display the various screens (the respective screensillustrated in FIGS. 7 and 8), received from the server apparatus 30 bythe communication section 27, and transmitting the information to theimage data generation portion 212.

The storage processing portion 213 performs read/write processes ofvarious programs or various data for the storage section 24. The storageprocessing portion 213 performs not only the process of storing the timeinformation and the measured data received from the data acquisitionportion 210 in the storage section 24 in correlation with each other,but also a process of storing various pieces of information calculatedby the swing analysis portion 211, the swing analysis data 248, or thelike in the storage section 24.

The swing analysis portion 211 performs a process of analyzing a swingaction of the user 2 by using the measured data (the measured datastored in the storage section 24) output from the sensor unit 10, thedata from the operation section 23, or the like, so as to generate theswing analysis data 248 including a time point (date and time) at whichthe swing was performed, identification information or the sex of theuser 2, the type of golf club 3, and information regarding a swingaction analysis result. Particularly, in the present embodiment, theswing analysis portion 211 calculates a value of each index of the swingas at least some of the information regarding the swing action analysisresult.

The swing analysis portion 211 may calculate at least one virtual planeas an index of the swing. For example, at least one virtual planeincludes a shaft plane SP (an example of a first virtual plane) whichwill be described later, and a Hogan plane HP (an example of a secondvirtual plane) which will be described later forming a first angle withthe shaft plane SP, and the swing analysis portion 211 may calculate the“shaft plane SP” and the “Hogan plane HP” as the indexes.

The swing analysis portion 211 may calculate a position of the head ofthe golf club 3 at a first timing during the backswing as an index ofthe swing. For example, the first timing is the time of halfway back atwhich the longitudinal direction of the golf club 3 becomes a directionalong the horizontal direction during the backswing, and the swinganalysis portion 211 may calculate a “position of the head at halfwayback” which will be described later as the index.

The swing analysis portion 211 may calculate a position of the head ofthe golf club 3 at a second timing during the downswing as an index ofthe swing. For example, the second timing is the time of halfway down atwhich the longitudinal direction of the golf club 3 becomes a directionalong the horizontal direction during the downswing, and the swinganalysis portion 211 may calculate a “position of the head at halfwaydown” which will be described later as the index.

The swing analysis portion 211 may calculate an index based on anincidence angle of the head of the golf club 3 at impact (at ballhitting), as an index of the swing. For example, the swing analysisportion 211 may calculate a “club path (incidence angle) ψ” or an“attack angle” which will be described later as the index.

The swing analysis portion 211 may calculate an index based on aninclination of the head of the golf club 3 at impact (at ball hitting)as an index of the swing. For example, the swing analysis portion 211may calculate a “(absolute) face angle φ” or a “relative face angle η”which will be described later as the index.

The swing analysis portion 211 may calculate an index based on a speedof the head of the golf club 3 at impact (at ball hitting) as an indexof the swing. For example, the swing analysis portion 211 may calculatea “head speed” which will be described later as the index.

The swing analysis portion 211 may calculate, as an index of the swing,an index based on a rotation angle αbout a rotation axis (hereinafter,referred to as about the long axis) of the shaft of the golf club 3 at apredetermined timing between the time of starting a backswing and thetime of impact (at ball hitting) with the longitudinal direction of theshaft as the rotation axis. The rotation angle αbout the long axis ofthe golf club 3 may be an angle by which the golf club 3 is rotatedabout the long axis from a reference timing to a predetermined timing.The reference timing may be the time of starting a backswing, and may bethe time of address. The predetermined timing may be the time (the timeof a top) at which a backswing transitions to a downswing. For example,the swing analysis portion 211 may calculate a “shaft axis rotationangle θ_(top) at top” which will be described later as the index.

The swing analysis portion 211 may calculate an index based on adeceleration amount of the grip of the golf club 3 during the downswingas an index of the swing. For example, the swing analysis portion 211may calculate a “grip deceleration ratio R_(v)” which will be describedlater as the index.

The swing analysis portion 211 may calculate an index based on adeceleration period of the grip of the golf club 3 during the downswingas an index of the swing. For example, the swing analysis portion 211may calculate a “grip deceleration time ratio R_(T)” which will bedescribed later as the index.

However, the swing analysis portion 211 may not calculate values of someof the indexes, and may calculate values of other indexes, asappropriate.

The image data generation portion 212 performs a process of generatingimage data corresponding to an image displayed on the display section25. For example, the image data generation portion 212 generates imagedata corresponding to the selection screen illustrated in FIG. 7, andthe display screen illustrated in FIG. 8, on the basis of various piecesof information received by the data acquisition portion 210.

The display processing portion 214 performs a process of displayingvarious images (including text, symbols, and the like in addition to animage corresponding to the image data generated by the image datageneration portion 212) on the display section 25. For example, thedisplay processing portion 214 displays the selection screen illustratedin FIG. 7, the display screen illustrated in FIG. 8, and the like, onthe display section 25, on the basis of the image data generated by theimage data generation portion 212. For example, the image datageneration portion 212 may display an image, text, or the like fornotifying the user 2 of permission of swing starting (an example ofpermission of motion starting) on the display section 25 in step S5 inFIG. 4. For example, the display processing portion 214 may display textinformation such as text or symbols indicating an analysis result in theswing analysis portion 211 on the display section 25 automatically or inresponse to an input operation performed by the user 2 after a swingaction of the user 2 is completed. Alternatively, a display section maybe provided in the sensor unit 10, and the display processing portion214 may transmit image data to the sensor unit 10 via the communicationsection 22, and various images, text, or the like may be displayed onthe display section of the sensor unit 10.

The sound output processing portion 215 performs a process of outputtingvarious sounds (including voices, buzzer sounds, and the like) from thesound output section 26. For example, the sound output processingportion 215 may output a sound for notifying the user 2 of permission ofswing starting from the sound output section 26 in step S5 in FIG. 4.For example, the sound output processing portion 215 may output a soundor a voice indicating an analysis result in the swing analysis portion211 from the sound output section 26 automatically or in response to aninput operation performed by the user 2 after a swing action of the user2 is completed. Alternatively, a sound output section may be provided inthe sensor unit 10, and the sound output processing portion 215 maytransmit various items of sound data or voice data to the sensor unit 10via the communication section 22, and may output various sounds orvoices from the sound output section of the sensor unit 10.

A vibration mechanism may be provided in the swing analysis apparatus 20or the sensor unit 10, and various pieces of information may beconverted into vibration information by the vibration mechanism so as tobe presented to the user 2.

1-3. Swing Analysis Process

In the present embodiment, when a position of the head of the golf club3 at address (during standing still) is set to the origin, an XYZcoordinate system (global coordinate system) is defined which has atarget line indicating a target hit ball direction as an X axis, an axison a horizontal plane which is perpendicular to the X axis as a Y axis,and a vertically upward direction (a direction opposite to thegravitational direction) as a Z axis. In order to calculate each indexvalue, the swing analysis portion 211 calculates a position and anattitude of the sensor unit 10 in a time series from the time of theaddress in the XYZ coordinate system (global coordinate system) by usingmeasured data (acceleration data and angular velocity data) in thesensor unit 10. The swing analysis portion 211 detects respectivetimings of the swing starting, the top, and the impact illustrated inFIG. 6, by using the measured data (acceleration data or angularvelocity data) in the sensor unit 10. The swing analysis portion 211calculates values of the respective indexes (for example, a shaft plane,a Hogan plane, a head position at halfway back, a head position athalfway down, a face angle, a club path (incidence angle), a shaft axisrotation angle αt top, a head speed, a grip deceleration ratio, and agrip deceleration time ratio) of the swing by using the time series dataof the position and the attitude of the sensor unit 10, and the timingsof the swing starting, the top, and the impact, so as to generate theswing analysis data 248.

Calculation of Position and Attitude of Sensor Unit 10

If the user 2 performs the action in step S4 in FIG. 4, first, the swinganalysis portion 211 determines that the user 2 stands still at anaddress attitude in a case where an amount of changes in accelerationdata measured by the acceleration sensor 12 does not continuously exceeda threshold value for a predetermined period of time. Next, the swinganalysis portion 211 computes an offset amount included in the measureddata by using the measured data (acceleration data and angular velocitydata) for the predetermined period of time. Next, the swing analysisportion 211 subtracts the offset amount from the measured data so as toperform bias correction, and computes a position and an attitude of thesensor unit 10 during a swing action of the user 2 (during the action instep S6 in FIG. 4) by using the bias-corrected measured data.

Specifically, first, the swing analysis portion 211 computes a position(initial position) of the sensor unit 10 during standing still (ataddress) of the user 2 in the XYZ coordinate system (global coordinatesystem) by using the acceleration data measured by the accelerationsensor 12, the golf club information 242, and the sensor attachmentposition information 246.

FIG. 10 is a plan view in which the golf club 3 and the sensor unit 10during standing still (at address) of the user 2 are viewed from anegative side of the X axis. The origin O (0,0,0) is set at a position61 of the head of the golf club 3, and coordinates of a position 62 of agrip end are (0, G_(Y), G_(Z)). Since the user 2 performs the action instep S4 in FIG. 4, the position 62 of the grip end or the initialposition of the sensor unit 10 has an X coordinate of 0, and is presenton a YZ plane. As illustrated in FIG. 10, the gravitational accelerationof 1 G is applied to the sensor unit 10 during standing still of theuser 2, and thus a relationship between a y axis acceleration y(0)measured by the sensor unit 10 and an inclined angle (an angle formedbetween the long axis of the shaft and the horizontal plane (XY plane))α of the shaft of the golf club 3 is expressed by Equation (1).

y(0)=1G·sin α  (1)

Therefore, the swing analysis portion 211 can calculate the inclinedangle α according to Equation (1) by using any acceleration data betweenany time points at address (during standing still).

Next, the swing analysis portion 211 subtracts a distance L_(SG) betweenthe sensor unit 10 and the grip end included in the sensor attachmentposition information 246 from a length L₁ of the shaft included in thegolf club information 242, so as to obtain a distance L_(SH) between thesensor unit 10 and the head. The swing analysis portion 211 sets, as theinitial position of the sensor unit 10, a position separated by thedistance L_(SH) from the position 61 (origin O) of the head in adirection (a negative direction of the y axis of the sensor unit 10)specified by the inclined angle α of the shaft.

The swing analysis portion 211 integrates subsequent acceleration dataso as to compute coordinates of a position from the initial position ofthe sensor unit 10 in a time series.

The swing analysis portion 211 computes an attitude (initial attitude)of the sensor unit 10 during standing still (at address) of the user 2in the XYZ coordinate system (global coordinate system) by usingacceleration data measured by the acceleration sensor 12. Since the user2 performs the action in step S4 in FIG. 4, the x axis of the sensorunit 10 matches the X axis of the XYZ coordinate system in terms ofdirection at address (during standing still) of the user 2, and the yaxis of the sensor unit 10 is present on the YZ plane. Therefore, theswing analysis portion 211 can specify the initial attitude of thesensor unit 10 on the basis of the inclined angle α of the shaft of thegolf club 3.

The swing analysis portion 211 computes changes in attitudes from theinitial attitude of the sensor unit 10 in a time series by performingrotation calculation using angular velocity data which is subsequentlymeasured by the angular velocity sensor 14. An attitude of the sensorunit 10 may be expressed by, for example, rotation angles (a roll angle,a pitch angle, and a yaw angle) about the X axis, the Y axis, and the Zaxis, or a quaternion.

The signal processing section 16 of the sensor unit 10 may compute anoffset amount of measured data so as to perform bias correction on themeasured data, and the acceleration sensor 12 and the angular velocitysensor 14 may have a bias correction function. In this case, it is notnecessary for the swing analysis portion 211 to perform bias correctionon the measured data.

Detection of Swing Starting, Top and Impact Timings

First, the swing analysis portion 211 detects a timing (impact timing)at which the user 2 hit a ball by using measured data. For example, theswing analysis portion 211 may compute a combined value of measured data(acceleration data or angular velocity data), and may detect an impacttiming (time point) on the basis of the combined value.

Specifically, first, the swing analysis portion 211 computes a combinedvalue n₀(t) of angular velocities at each time point t by using theangular velocity data (bias-corrected angular velocity data for eachtime point t). For example, if the angular velocity data items at thetime point t are respectively indicated by x(t), y(t), and z(t), theswing analysis portion 211 computes the combined value n₀(t) of theangular velocities according to the following Equation (2).

n ₀(t)=√{square root over (x(t)² +y(t)² +z(t)²)}  (2)

Next, the swing analysis portion 211 converts the combined value n₀(t)of the angular velocities at each time point t into a combined valuen(t) which is normalized (scale-conversion) within a predeterminedrange. For example, if the maximum value of the combined value of theangular velocities in an acquisition period of measured data is max(n₀), the swing analysis portion 211 converts the combined value n₀(t)of the angular velocities into the combined value n(t) which isnormalized within a range of 0 to 100 according to the followingEquation (3).

$\begin{matrix}{{n(t)} = \frac{100 \times {n_{0}(t)}}{\max \left( n_{0} \right)}} & (3)\end{matrix}$

Next, the swing analysis portion 211 computes a derivative do (t) of thenormalized combined value n (t) at each time point t. For example, if acycle for measuring three-axis angular velocity data items is indicatedby Δt, the swing analysis portion 211 computes the derivative(difference) dn(t) of the combined value of the angular velocities atthe time point t by using the following Equation (4).

dn(t)=n(t)−n(t−Δt)   (4)

FIG. 11 illustrates examples of three-axis angular velocity data itemsx(t), y(t) and z(t) obtained when the user 2 hits the golf ball 4 byperforming a swing. In FIG. 11, a transverse axis expresses time (msec),and a longitudinal axis expresses angular velocity (dps).

FIG. 12 is a diagram in which the combined value n₀(t) of the three-axisangular velocities is computed according to Equation (2) by using thethree-axis angular velocity data items x(t), y(t) and z(t) in FIG. 11,and then the combined value n(t) normalized to 0 to 100 according toEquation (3) is displayed in a graph. In FIG. 12, a transverse axisexpresses time (msec), and a longitudinal axis expresses a norm of theangular velocity.

FIG. 13 is a diagram in which the derivative dn(t) is calculatedaccording to Equation (4) on the basis of the combined value n(t) of thethree-axis angular velocities in FIG. 12, and is displayed in a graph.In FIG. 13, a transverse axis expresses time (msec), and a longitudinalaxis expresses a derivative value of the combined value of thethree-axis angular velocities. In FIGS. 11 and 12, the transverse axisis displayed at 0 seconds to 5 seconds, but, in FIG. 13, the transverseaxis is displayed at 2 seconds to 2.8 seconds so that changes in thederivative value before and after impact can be understood.

Next, of time points at which a value of the derivative do (t) of thecombined value becomes the maximum and the minimum, the swing analysisportion 211 specifies the earlier time point as an impact time pointt_(impact) (impact timing) (refer to FIG. 13). It is considered thatswing speed is the maximum at the moment of impact in a typical golfswing. In addition, since it is considered that a value of the combinedvalue of the angular velocities also changes according to a swing speed,the swing analysis portion 211 can capture a timing at which aderivative value of the combined value of the angular velocities is themaximum or the minimum (that is, a timing at which the derivative valueof the combined value of the angular velocities is a positive maximumvalue or a negative minimum value) in a series of swing actions as theimpact timing. Since the golf club 3 vibrates due to the impact, atiming at which a derivative value of the combined value of the angularvelocities is the maximum and a timing at which a derivative value ofthe combined value of the angular velocities is the minimum may occur inpairs, and, of the two timings, the earlier timing may be the moment ofthe impact.

Next, the swing analysis portion 211 specifies a time point of a minimumpoint at which the combined value n(t) is close to 0 before the impacttime point t_(impact), as a top time point t_(top) (top timing) (referto FIG. 12). It is considered that, in a typical golf swing, an actiontemporarily stops at the top after starting the swing, then a swingspeed increases, and finally impact occurs. Therefore, the swinganalysis portion 211 can capture a timing at which the combined value ofthe angular velocities is close to 0 and becomes the minimum before theimpact timing, as the top timing.

Next, the swing analysis portion 211 sets an interval in which thecombined value n(t) is equal to or smaller than a predeterminedthreshold value before and after the top time point t_(top), as a topinterval, and detects a last time point at which the combined value n(t)is equal to or smaller than the predetermined threshold value before astarting time point of the top interval, as a swing starting (backswingstarting) time point t_(start) (refer to FIG. 12). It is hardlyconsidered that, in a typical golf swing, a swing action is started froma standing still state, and the swing action is stopped till the top.Therefore, the swing analysis portion 211 can capture the last timing atwhich the combined value of the angular velocities is equal to orsmaller than the predetermined threshold value before the top intervalas a timing of starting the swing action. The swing analysis portion 211may detect a time point of the minimum point at which the combined valuen(t) is close to 0 before the top time point t_(top) as the swingstarting time point t_(start).

The swing analysis portion 211 may also detect each of a swing startingtiming, a top timing, and an impact timing by using three-axisacceleration data in the same manner.

Calculation of Shaft Plane and Hogan Plane

The shaft plane is a first virtual plane specified by a target line(target hit ball direction) and the longitudinal direction of the shaftof the golf club 3 at address (standing still state) of the user 2before starting a swing. The Hogan plane is a second virtual planespecified by a virtual line connecting the vicinity of the shoulder (theshoulder or the base of the neck) of the user 2 to the head of the golfclub (or the golf ball 4), and the target line (target hit balldirection), at address of the user 2.

FIG. 14 is a diagram illustrating the shaft plane and the Hogan plane.FIG. 14 displays the X axis, the Y axis, and the Z axis of the XYZcoordinate system (global coordinate system).

As illustrated in FIG. 14, in the present embodiment, a virtual planewhich includes a first line segment 51 as a first axis along a targethit ball direction and a second line segment 52 as a second axis alongthe longitudinal direction of the shaft of the golf club 3, and has fourvertices such as U1, U2, S1, and S2, as the shaft plane SP (firstvirtual plane). In the present embodiment, the position 61 of the headof the golf club 3 at address is set as the origin O (0,0,0) of the XYZcoordinate system, and the second line segment 52 is a line segmentconnecting the position 61 (origin O) of the head of the golf club 3 tothe position 62 of the grip end. The first line segment 51 is a linesegment having a length UL in which U1 and U2 on the X axis are bothends, and the origin O is a midpoint. Since the user 2 performs theaction in step S4 in FIG. 4 at address, and thus the shaft of the golfclub 3 is perpendicular to the target line (X axis), the first linesegment 51 is a line segment orthogonal to the longitudinal direction ofthe shaft of the golf club 3, that is, the second line segment 52. Theswing analysis portion 211 calculates coordinates of the four verticesU1, U2, S1, and S2 of the shaft plane SP in the XYZ coordinate system.

Specifically, first, the swing analysis portion 211 computes coordinates(0, G_(Y), G_(Z)) of the position 62 of the grip end of the golf club 3by using the inclined angle α and the length L₁ of the shaft included inthe golf club information 242. As illustrated in FIG. 10, the swinganalysis portion 211 may compute G_(Y) and G_(Z) by using the length L₁of the shaft and the inclined angle α according to Equations (5) and(6).

G _(Y) =L ₁·cos α  (5)

G _(Z) =L ₁·sin α  (6)

Next, the swing analysis portion 211 multiplies the coordinates (0,G_(Y), G_(Z)) of the position 62 of the grip end of the golf club 3 by ascale factor S so as to compute coordinates (0, S_(Y), S_(Z)) of amidpoint S3 of the vertex S1 and the vertex S2 of the shaft plane SP. Inother words, the swing analysis portion 211 computes S_(Y) and S_(Z)according to Equations (7) and (8), respectively.

S _(y) =G _(Y) ·S   (7)

S _(Z) =G _(Z) ·S   (8)

FIG. 15 is a view in which a sectional view of the shaft plane SP inFIG. 14 which is cut in the YZ plane is viewed from the negative side ofthe X axis. As illustrated in FIG. 15, a length (a width of the shaftplane SP in a direction orthogonal to the X axis) of a line segmentconnecting the midpoint S3 of the vertex S1 and the vertex S2 to theorigin O is S times the length L₁ of the second line segment 52. Thescale factor S is set to a value at which a trajectory of the golf club3 during a swing action of the user 2 enters the shaft plane SP. Forexample, if a length of the arms of the user 2 is indicated by L₂, thescale factor S maybe set as in Equation (9) so that the width S×L₁ ofthe shaft plane SP in the direction orthogonal to the X axis is twicethe sum of the length L₁ of the shaft and the length L₂ of the arms.

$\begin{matrix}{S = \frac{2 \cdot \left( {L_{1} + L_{2}} \right)}{L_{1}}} & (9)\end{matrix}$

The length L₂ of the arms of the user 2 is associated with a height L₀of the user 2. The length L₂ of the arms is expressed by a correlationexpression such as Equation (10) in a case where the user 2 is a male,and is expressed by a correlation expression such as Equation (11) in acase where the user 2 is a female, on the basis of statisticalinformation.

L ₂=0.41×L ₀−45.5 [mm]  (10)

L ₂=0.46×L ₀−126.9 [mm]  (11)

Therefore, the swing analysis portion 211 may calculate the length L₂ ofthe arms of the user according to Equation (10) or Equation (11) byusing the height L₀ and the sex of the user 2 included in the physicalinformation 244.

Next, the swing analysis portion 211 computes coordinates (−UL/2, 0, 0)of the vertex U1 of the shaft plane SP, coordinates (UL/2, 0, 0) of avertex U2, coordinates (−UL/2, S_(Y), S_(Z)) of the vertex S1, andcoordinates (UL/2, S_(Y), S_(Z)) of the vertex S2 by using thecoordinates (0, S_(Y), S_(Z)) of the midpoint S3 and a width (the lengthof the first line segment 51) UL of the shaft plane SP in the X axisdirection. The width UL in the X axis direction is set to a value atwhich a trajectory of the golf club 3 during a swing action of the user2 enters the shaft plane SP. For example, the width UL in the X axisdirection may be set to be same as the width S×L₁ in the directionorthogonal to the X axis, that is, twice the sum of the length L₁ of theshaft and the length L₂ of the arms.

In the above-described manner, the swing analysis portion 211 cancalculate the coordinates of the four vertices U1, U2, S1, and S2 of theshaft plane SP.

As illustrated in FIG. 14, in the present embodiment, a virtual planewhich includes a first line segment 51 as a first axis and a third linesegment 53 as a third axis, and has four vertices such as U1, U2, H1,and H2, is used as the Hogan plane HP (second virtual plane). The thirdline segment 53 is a line segment connecting a predetermined position 63in the vicinity of a line segment connecting both of the shoulders ofthe user 2, to the position 61 of the head of the golf club 3. However,the third line segment 53 may be a line segment connecting thepredetermined position 63 to a position of the golf ball 4. The swinganalysis portion 211 calculates respective coordinates of the fourvertices U1, U2, H1, and H2 of the Hogan plane HP in the XYZ coordinatesystem.

Specifically, first, the swing analysis portion 211 estimates thepredetermined position 63 by using the coordinates (0, G_(Y), G_(Z)) ofthe position 62 of the grip end of the golf club 3 at address (duringstanding still), and the length L₂ of the arms of the user 2 based onthe physical information 244, and computes coordinates (A_(X), A_(Y),A_(Z)) thereof.

FIG. 16 is a view in which a sectional view of the Hogan plane HPillustrated in FIG. 14 which is cut in the YZ plane is viewed from thenegative side of the X axis. In FIG. 16, a midpoint of the line segmentconnecting both of the shoulders of the user 2 is the predeterminedposition 63, and the predetermined position 63 is present on the YZplane. Therefore, an X coordinate A_(X) of the predetermined position 63is 0. As illustrated in FIG. 16, the swing analysis portion 211estimates, as the predetermined position 63, a position obtained bymoving the position 62 of the grip end of the golf club 3 by the lengthL₂ of the arms of the user 2 in a positive direction along the Z axis.Therefore, the swing analysis portion 211 sets a Y coordinate A_(Y) ofthe predetermined position 63 to be the same as the Y coordinate G_(Y)of the position 62 of the grip end. The swing analysis portion 211computes a Z coordinate A_(Z) of the predetermined position 63 as a sumof the Z coordinate G_(Z) of the position 62 of the grip end and thelength L₂ of the arms of the user 2 as in Equation (12).

A _(Z) =G _(Z) +L ₂   (12)

Next, the swing analysis portion 211 multiplies the Y coordinate A_(Y)and the Z coordinate A_(Z) of the predetermined position 63 by a scalefactor H, so as to compute coordinates (0, H_(Y), H_(Z)) of a midpointH3 of the vertex H1 and the vertex H2 of the Hogan plane HP. In otherwords, the swing analysis portion 211 computes H_(Y) and H_(Z) accordingto Equation (13) and Equation (14), respectively.

H _(Y) =A _(Y) ·H   (13)

H _(Z) =A _(Z) ·H   (14)

As illustrated in FIG. 16, a length (a width of the Hogan plane HP in adirection orthogonal to the X axis) of a line segment connecting themidpoint H3 of the vertex H1 and the vertex H2 to the origin O is Htimes the length L₃ of the third line segment 53. The scale factor H isset to a value at which a trajectory of the golf club 3 during a swingaction of the user 2 enters the Hogan plane HP. For example, the Hoganplane HP may have the same shape and size as the shape and the size ofthe shaft plane SP. In this case, the width H×L₃ of the Hogan plane HPin the direction orthogonal to the X axis matches the width S×L₁ of theshaft plane SP in the direction orthogonal to the X axis, and is twicethe sum of the length L₁ of the shaft of the golf club 3 and the lengthL₂ of the arms of the user 2. Therefore, the swing analysis portion 211may compute the scale factor H according to Equation (15).

$\begin{matrix}{H = \frac{2 \cdot \left( {L_{1} + L_{2}} \right)}{L_{3}}} & (15)\end{matrix}$

The swing analysis portion 211 may compute the length L₃ of the thirdline segment 53 according to Equation (13) by using the Y coordinateA_(Y) and the Z coordinate A_(Z) of the predetermined position 63.

Next, the swing analysis portion 211 computes coordinates (−UL/2, H_(Y),H_(Z)) of the vertex H1 of the Hogan plane HP, and coordinates (UL/2,H_(Y), H_(Z)) of the vertex H2 by using the coordinates (0, H_(Y),H_(Z)) of the midpoint H3 and a width (the length of the first linesegment 51) UL of the Hogan plane HP in the X axis direction. The twovertices U1 and U2 of the Hogan plane HP are the same as those of theshaft plane SP, and thus the swing analysis portion 211 does not need tocompute coordinates of the vertices U1 and U2 of the Hogan plane HPagain.

In the above-described manner, the swing analysis portion 211 cancalculate the coordinates of the four vertices U1, U2, H1, and H2 of theHogan plane HP.

A region interposed between the shaft plane SP (first virtual plane) andthe Hogan plane HP (second virtual plane) is referred to as a “V zone”,and a trajectory of a hit ball (a ball line) may be estimated to someextent on the basis of a relationship between a position of the head ofthe golf club 3 and the V zone during a backswing or a downswing. Forexample, in a case where the head of the golf club 3 is present in aspace lower than the V zone at a predetermined timing during a backswingor a downswing, a hit ball is likely to fly in a hook direction. In acase where the head of the golf club 3 is present in a space higher thanthe V zone at a predetermined timing during a backswing or a downswing,a hit ball is likely to fly in a slice direction. In the presentembodiment, as is clear from FIG. 16, a first angle β formed between theshaft plane SP and the Hogan plane HP is determined depending on thelength L₁ of the shaft of the golf club 3 and the length L₂ of the armsof the user 2. In other words, since the first angle β is not a fixedvalue, and is determined depending on the type of golf club 3 orphysical features of the user 2, the more appropriate shaft plane SP andHogan plane HP (V zone) are calculated as an index for diagnosing aswing of the user 2.

Calculation of Head Positions at Halfway Back and Halfway Down

Ahead position at halfway back is a position of the head at the momentof the halfway back, right before the halfway back, or right after thehalfway back, and a head position at halfway down is a position of thehead at the moment of the halfway down, right before the halfway down,or right after the halfway down.

First, the swing analysis portion 211 computes a position of the headand a position of the grip end at each time point t by using theposition and the attitude of the sensor unit 10 at each time point tfrom the swing start time point t_(start) to the impact time pointt_(impact).

Specifically, the swing analysis portion 211 uses a position separatedby the distance L_(SH) in the positive direction of the y axis specifiedby the attitude of the sensor unit 10, from the position of the sensorunit 10 at each time point t as a position of a head, and computescoordinates of the position of the head. As described above, thedistance L_(SH) is a distance between the sensor unit 10 and the head.The swing analysis portion 211 uses a position separated by the distanceL_(SG) in the negative direction of the y axis specified by the attitudeof the sensor unit 10, from the position of the sensor unit 10 at eachtime point t as a position of a grip end, and computes coordinates ofthe position of the grip end. As described above, the distance L_(SG) isa distance between the sensor unit 10 and the grip end.

Next, the swing analysis portion 211 detects a halfway back timing and ahalfway down timing by using the coordinates of the position of the headand the coordinates of the position of the grip end.

Specifically, the swing analysis portion 211 computes a difference ΔZbetween a Z coordinate of the position of the head and a Z coordinate ofthe position of the grip end at each time point t from the swing starttime point t_(start) to the impact time point t_(impact). The swinganalysis portion 211 detects a time point t_(HWB) at which a sign of ΔZis inverted between the swing start time point t_(start) and the toptime point t_(top), as the halfway back timing. The swing analysisportion 211 detects a time point t_(HWD) at which a sign of ΔZ isinverted between the top time point t_(top) and the impact time pointt_(impact), as the halfway down timing.

The swing analysis portion 211 uses the position of the head at the timepoint t_(HWB) as a position of the head at halfway back, and uses theposition of the head at the time point t_(HWD) as a position of the headat halfway down.

Calculation of Head Speed

Ahead speed is the magnitude of a speed of the head at impact (themoment of the impact, right before the impact, or right after theimpact). For example, the swing analysis portion 211 computes a speed ofthe head at the impact time point t_(impact) on the basis of differencesbetween the coordinates of the position of the head at the impact timepoint t_(impact) and coordinates of a position of the head at theprevious time point. The swing analysis portion 211 computes themagnitude of the speed of the head as the head speed.

Calculation of Face Angle and Club Path (Incidence Angle)

The face angle is an index based on an inclination of the head of thegolf club 3 at impact, and the club path (incidence angle) is an indexbased on a trajectory of the head of the golf club 3 at impact.

FIG. 17 is a diagram for explaining the face angle and the club path(incidence angle). FIG. 17 illustrates the golf club 3 (only the head isillustrated) on the XY plane viewed from a positive side of the Z axisin the XYZ coordinate system. In FIG. 17, the reference numeral 74indicates a face surface (hitting surface) of the golf club 3, and thereference numeral 75 indicates a ball hitting point. The referencenumeral 70 indicates a target line indicating a target hit balldirection, and the reference numeral 71 indicates a plane orthogonal tothe target line 70. The reference numeral 76 indicates a curveindicating a trajectory of the head of the golf club 3, and thereference numeral 72 is a tangential line at the ball hitting point 75for the curve 76. In this case, the face angle φ is an angle formedbetween the plane 71 and the face surface 74, that is, an angle formedbetween a straight line 73 orthogonal to the face surface 74, and thetarget line 70. The club path (incidence angle) ψ is an angle formedbetween the tangential line 72 (a direction in which the head in the XYplane passes through the ball hitting point 75) and the target line 70.

For example, assuming that an angle formed between the face surface ofthe head and the x axis direction is normally constant (for example,orthogonal), the swing analysis portion 211 computes a direction of astraight line orthogonal to the face surface on the basis of theattitude of the sensor unit 10 at the impact time point t_(impact). Theswing analysis portion 211 uses, a straight line obtained by setting a Zaxis component of the direction of the straight line to 0, as adirection of the straight line 73, and computes an angle (face angle) φformed between the straight line 73 and the target line 70.

For example, the swing analysis portion 211 uses a direction of a speed(that is, a speed of the head in the XY plane) obtained by setting a Zaxis component of a speed of the head at the impact time pointt_(impact) to 0, as a direction of the tangential line 72, and computesan angle (club path (incidence angle)) ψ formed between the tangentialline 72 and the target line 70.

The face angle φ indicates an inclination of the face surface 74 withthe target line 70 whose direction is fixed regardless of an incidencedirection of the head to the ball hitting point 75 as a reference, andis thus also referred to as an absolute face angle. In contrast, anangle η formed between the straight line 73 and the tangential line 72indicates an inclination of the face surface 74 with an incidencedirection of the head to the ball hitting point 75 as a reference, andis thus referred to as a relative face angle. The relative face angle ηis an angle obtained by subtracting the club path (incidence angle) ψfrom the (absolute) face angle φ.

Calculation of Attack Angle

An attack angle is an index based on a trajectory of the head of thegolf club 3 at the impact time point t_(impact) in the same manner asthe club path (incidence angle). However, the attack angle is obtainedas a result of an angle of a trajectory being computed in a plane whichis different from the plane of the club path (incidence angle).

The swing analysis portion 211 computes an angle formed between avelocity vector of the head and the Z axis in the XZ plane at the impacttime point t_(impact), as the attack angle. For example, if a movementdirection of the head at the impact time point t_(impact) is a directionof a so-called upper blow, the attack angle is a positive value, theattack angle is a negative value in a direction of a so-called downblow, and the attack angle is zero in a direction of a level blow.

Calculation of Swing Rhythm

A swing rhythm is an index indicating a proportion of the time requiredin each section of a swing.

The swing analysis portion 211 partitions, for example, the entire swingperiod at the swing start time point t_(start), the halfway back timepoint t_(HWB), the top time point t_(top), the halfway down time pointt_(HWD), the grip deceleration start time point t_(vmax), and the impacttime point t_(impact), so as to divide the entire swing period into aplurality of sections, and computes the time required for each section.

The swing analysis portion 211 computes a ratio between the timesrequired for two different sections, as a swing rhythm. Two differentsections may be two sections not overlapping each other, and may be twosections one of which includes the other section. Two different sectionsmay be two sections which are designated by the user 2 in advance.

For example, the swing analysis portion 211 computes a ratio obtained bydividing the time required for a backswing (the time required for thesection from the swing start time point t_(start) to the top time pointt_(top)) by the time required for a downswing (the time required for thesection from the top time point t_(top) to the impact time pointt_(impact)), as the swing rhythm.

Calculation of Hands-Up Angle

A hands-up angle is one of indexes indicating an attitude deviation ofthe shaft between the swing start time point t_(start) and the impacttime point t_(impact), and is an index indicating deviation between aninclined angle α (t_(start)) of the shaft in a lie angle direction atthe swing start time point t_(start) and an inclined angle α(t_(impact)) of the shaft in a lie angle direction at the impact timepoint t_(impact). Instead of the inclined angle α (t_(start)) of theshaft in a lie angle direction at the swing start time point t_(start),an inclined angle α (t_(address)) of the shaft in a lie angle directionat the address time point t_(address) may be used. The inclined angle αin a lie angle direction is an angle indicated by the reference sign αin FIG. 10, and is an angle formed between the y axis and the Y axis inthe YZ plane.

The swing analysis portion 211 calculates an inclined angle α(t_(start)) at the time of swing starting, for example, on the basis ofan attitude (an attitude expressed in the global coordinate system) ofthe golf club 3 at the swing start time point t_(start).

The swing analysis portion 211 calculates an inclined angle α(t_(impact)) at the impact time point t_(impact), for example, on thebasis of an attitude (an attitude expressed in the global coordinatesystem) of the golf club 3 at the impact time point t_(impact).

The swing analysis portion 211 calculates an inclined angle α(t_(address)) at the address time point t_(address), for example, on thebasis of a ratio (a_(y)/a_(z)) between a z-axis acceleration componenta_(z) and a y-axis acceleration component a_(y) at the address timepoint t_(address). The swing analysis portion 211 may apply a y-axisacceleration component a_(y) to “y(0) ” in Equation (1) so as to obtainan inclined angle α (t_(address)) at the address time point.

For example, the swing analysis portion 211 subtracts the inclined angleα (t_(start)) at the swing start time point t_(start) from the inclinedangle α (t_(impact)) at the impact time point t_(impact), so as tocalculated a hands-up angle Δα=α(t_(impact))−α(t_(start)).

For example, the swing analysis portion 211 may subtract the inclinedangle α (t_(address)) at the address time point t_(address) from theinclined angle α (t_(impact)) at the impact time point t_(impact), so asto calculate a hands-up angle Δα=α(t_(impact))−α(t_(address)).

Calculation of Shaft Axis Rotation Angle at Top

The shaft axis rotation angle θ_(top) at top is an angle (relativerotation angle) by which the golf club 3 is rotated about a shaft axisfrom a reference timing to a top timing. The reference timing is, forexample, the time of starting a backswing, or the time of address. Inthe present embodiment, in a case where the user 2 is a right-handedgolfer, a right-handed screw tightening direction toward the tip end onthe head side of the golf club 3 (a clockwise direction when the head isviewed from the grip end side) is a positive direction of the shaft axisrotation angle θ_(top). Conversely, in a case where the user 2 is aleft-handed golfer, a left-handed screw tightening direction toward thetip end on the head side of the golf club 3 (a counterclockwisedirection when the head is viewed from the grip end side) is a positivedirection of the shaft axis rotation angle θ_(top).

FIG. 18 is a diagram illustrating an example of a temporal change of theshaft axis rotation angle from starting of a swing (starting of abackswing) to impact. In FIG. 18, a transverse axis expresses time (s),and a longitudinal axis expresses a shaft axis rotation angle (deg).FIG. 18 illustrates the shaft axis rotation angle θ_(top) at top withthe time of starting a swing (the time of starting a backswing) as areference timing (at which the shaft axis rotation angle is 0°).

In the present embodiment, as illustrated in FIG. 3, the y axis of thesensor unit 10 substantially matches the longitudinal direction of theshaft of the golf club 3 (the longitudinal direction of the golf club3). Therefore, for example, the swing analysis portion 211time-integrates a y axis angular velocity included in angular velocitydata from the swing starting (backswing starting) time point t_(start)or the time of address to the top time point t_(top) (at top), so as tocompute the shaft axis rotation angle θ_(top). Similarly, the swinganalysis portion 211 time-integrates a y axis angular velocity includedin angular velocity data from the swing starting (backswing starting)time point t_(start) or the time of address to the halfway back timepoint t_(HWB), so as to compute a shaft axis rotation angle θ_(HWB) atthe halfway back time point t_(HWB).

Calculation of Grip Deceleration Ratio and Grip Deceleration Time Ratio

The grip deceleration ratio is an index based on a grip decelerationamount, and is a ratio between a speed of the grip when the grip startsto be decelerated during the downswing, and a speed of the grip atimpact. The grip deceleration time ratio is an index based on a gripdeceleration period, and is a ratio between a period of time from thetime at which the grip starts to be decelerated during the downswing tothe time of impact, and a period of time of the downswing. A speed ofthe grip is preferably a speed of a portion held by the user 2, but maybe a speed of any portion of the grip (for example, the grip end), andmay be a speed of a peripheral portion of the grip.

FIG. 19 is a diagram illustrating an example of a temporal change of aspeed of the grip during the downswing. In FIG. 19, a transverse axisexpresses time (s), and a longitudinal axis expresses a speed (m/s) ofthe grip. In FIG. 19, if a speed (the maximum speed of the grip) whenthe grip starts to be decelerated is indicated by V1, and a speed of thegrip at impact is indicated by V2, a grip deceleration ratio R_(v)(unit: %) is expressed by the following Equation (16).

R _(V) =V1−V2/V1×100(%)   (16)

In FIG. 19, if a period of time from the time of top to the time atwhich the grip starts to be decelerated is indicated by T1, and a periodof time from the time at which the grip starts to be decelerated duringthe downswing to the time of impact is indicated by T2, a gripdeceleration time ratio R_(T) (unit: %) is expressed by the followingEquation (17).

R _(T) =T2/T1+T2×100(%)   (17)

For example, the sensor unit 10 may be attached to the vicinity of aportion of the golf club 3 held by the user 2, and a speed of the sensorunit 10 may be regarded as a speed of the grip. Therefore, first, theswing analysis portion 211 computes a speed of the sensor unit 10 at thetime point t on the basis of differences between coordinates of aposition of the sensor unit 10 at each time point t from the top timepoint t_(top) to the impact time point t_(impact) (during the downswing)and coordinates of a position of the sensor unit 10 at the previous timepoint.

Next, the swing analysis portion 211 computes the magnitude of the speedof the sensor unit 10 at each time point t, sets the maximum valuethereof as V1, and sets the magnitude of the speed at the impact timepoint t_(impact) as V2. The swing analysis portion 211 specifies a timepoint t_(vmax) at which the magnitude of the speed of the sensor unit 10becomes the maximum value V1. The swing analysis portion 211 computesT1=t_(vmax)−t_(top), and T2=t_(impact)−t_(vmax). The swing analysisportion 211 computes the grip deceleration ratio R_(V) and the gripdeceleration time ratio R_(T) according to Equations (16) and (17)respectively.

The swing analysis portion 211 may regard a speed of the grip end as aspeed of the grip, and may compute the speed of the grip end on thebasis of coordinates of a position of the grip end at each time point tduring the downswing, so as to obtain the grip deceleration ratio R_(V)and the grip deceleration time ratio R_(T) through the above-describedcomputation.

Calculation of Indexes of “V Zone” Item

The swing analysis portion 211 calculates, as indexes, a region in whicha head position is included at the halfway back time point t_(HWB), aregion in which a head position is included at the halfway down timepoint t_(HWD), a region in which a head position is included at the gripdeceleration start time point t_(vmax), and a region in which a headposition is included at the top time point t_(top). Interfaces of aplurality of regions are determined on the basis of the shaft plane SPand the Hogan plane HP (V zone) which are virtual planes definedaccording to an address attitude of the user 2.

FIG. 20 is a diagram illustrating examples of relationships among theshaft plane SP and the Hogan plane HP (V zone), and a plurality ofregions (a lower part in FIG. 20 schematically illustrates an example ofthe shaft plane SP, the Hogan plane HP, and an attitude of the user 2).FIG. 20 illustrates relationships among the shaft plane SP, the Hoganplane HP, and five regions A to E when viewed from a negative side ofthe X axis (when projected onto the YZ plane). The region B is apredetermined space including the Hogan plane HP, and the region D is apredetermined space including the shaft plane SP. The region C is aspace interposed between the region B and the region D (a space betweenan interface S_(BC) with the region B and an interface S_(CD) with theregion D). The region A is a space in contact with the region B in aninterface S_(AB) on an opposite side to the region C. The region E is aspace in contact with the region D in an interface S_(DE) on an oppositeside to the region C.

There maybe various methods of setting the interface S_(AB), theinterface S_(BC), the interface S_(CD), and the interface S_(DE). As anexample, the interfaces may be set so that, on the YZ plane, the Hoganplane HP is located exactly at the center of the interface S_(AB) andthe interface S_(BC), the shaft plane SP is located exactly at thecenter of the interface S_(CD) and the interface S_(DE), and angles ofthe region B, the region C, and the region D about the origin O (X axis)are the same as each other. In other words, with respect to the firstangle β formed between the shaft plane SP and the Hogan plane HP, ifeach of angles formed between the Hogan plane HP, and the interfaceS_(AB) and the interface S_(BC) is set to β/4, and each of angles formedbetween the shaft plane SP, and the interface S_(CD) and the interfaceS_(DE) is set to β/4, angles of the region B, the region C, and theregion D are all set to β/2.

Since a swing that causes a Y coordinate of a head position at halfwayback or halfway down to be negative cannot be expected, an interface ofthe region A opposite to the interface S_(AB) is set in the XZ plane inFIG. 20. Similarly, a swing that causes a Z coordinate of a headposition at halfway back or halfway down to be negative cannot beexpected, and an interface of the region E opposite to the interfaceS_(DE) is set in the XY plane. Of course, an interface of the region Aor the region E may be set so that an angle of the region A or theregion E about the origin O (X axis) is the same as angles of the regionB, the region C, and the region D.

Specifically, first, the swing analysis portion 211 sets the interfaceS_(AB), the interface S_(BC), the interface S_(CD), and the interfaceS_(DE) of the regions A to E on the basis of coordinates of each of thefour vertices U1, U2, S1, and S2 of the shaft plane SP and coordinatesof each of the four vertices U1, U2, H1, and H2 of the Hogan plane HP.

Next, the swing analysis portion 211 determines in which region of theregions A to E coordinates of a head position at the halfway back timepoint t_(HWB), coordinates of a head position at the halfway down timepoint t_(HWD), coordinates of a head position at the grip decelerationstart time point t_(vmax), and coordinates of a head position at the toptime point t_(top) are included.

Procedures of Swing Analysis Process

FIG. 21 is a flowchart illustrating examples of procedures of a swinganalysis process performed by the processing section 21. The processingsection 21 performs the swing analysis process, for example, accordingto the procedures shown in the flowchart of FIG. 21 by executing theswing analysis program 240 stored in the storage section 24.Hereinafter, the flowchart of FIG. 21 will be described.

First, the processing section 21 waits for the user 2 to perform ameasurement starting operation (the operation in step S2 in FIG. 4) (Nin step S10), transmits a measurement starting command to the sensorunit 10 if the measurement starting operation is performed (Y in stepS10), and starts to acquire measured data from the sensor unit 10 (stepS12).

Next, the processing section 21 instructs the user 2 to take an addressattitude (step S14). The user 2 takes the address attitude in responseto the instruction, and stands still (step S4 in FIG. 4).

Next, the processing section 21 determines whether or not the golf club3 stands still at an accurate attitude for a predetermined period oftime by using the measured data acquired from the sensor unit 10 (stepS16), and notifies the user 2 of permission of swing starting (step S18)if the golf club stands still (Y in step S16), and proceeds to a finishdetermination process (step S24) if the golf club does not stand still.The processing section 21 outputs, for example, a predetermined sound,or an LED is provided in the sensor unit 10, and the LED is lighted, sothat the user 2 is notified of permission of swing starting. The user 2confirms the notification and then starts a swing action (the action instep S6 in FIG. 4).

Next, the processing section 21 determines whether or not impact isdetected within a predetermined period from the permission of the swing(step S18) on the basis of the measured data acquired from the sensorunit 10 (step S20), proceeds to a swing analysis data generation process(step S22) if the impact is detected (Y in step S20), and proceeds tothe finish determination process (step S24) if the impact is notdetected (N in step S20).

Next, the processing section 21 extracts measured data during the swingbefore and after the impact, from the measured data acquired from thesensor unit 10, calculates various indexes and trajectories on the basisof the measured data during the swing, generates swing analysis dataincluding the indexes and the trajectories, and transmits the swinganalysis data to the server apparatus 30 (step S22). The processingsection 21 uses the measured data in the period in which the golf club 3stands still at an accurate attitude, for performing bias correction onthe measured data during the swing and setting global coordinates. Theprocessing section 21 may cause the measured data itself (so-called rawdata) during the swing to be included in the swing analysis data whichis transmitted to the server apparatus 30.

Next, the processing section 21 determines whether or not a measurementfinishing operation has been performed by the user 2 (step S24),finishes the flow if the operation has been performed (Y instep S24),and proceeds to the address instruction process (step S14) if theoperation has not been performed (N in step S24).

In the flowchart of FIG. 21, order of the respective steps maybe changedas appropriate within an allowable range, some of the steps may beomitted or changed, and other steps may be added thereto.

1-4. Configuration of Sever Apparatus

FIG. 22 is a diagram illustrating a configuration example of the serverapparatus 30. As illustrated in FIG. 22, in the present embodiment, theserver apparatus 30 is configured to include a processing section 31, acommunication section 32, and a storage section 34. However, the serverapparatus 30 may have a configuration in which some of the constituentelements are deleted or changed as appropriate, or may have aconfiguration in which other constituent elements are added thereto.

The storage section 34 is constituted of, for example, various ICmemories such as a ROM, a flash ROM, and a RAM, or a recording mediumsuch as a hard disk or a memory card. The storage section 34 stores aprogram for the processing section 31 performing various calculationprocesses or a control process, or various programs or data forrealizing application functions.

In the present embodiment, the storage section 34 stores (preserves) aswing analysis data list 341 including a plurality of items of swinganalysis data 248 generated by the swing analysis apparatus 20. In otherwords, the swing analysis data 248 generated whenever the processingsection 21 of the swing analysis apparatus 20 analyzes a swing action ofthe user 2 is sequentially added to the swing analysis data list 341.

The storage section 34 is used as a work area of the processing section31, and temporarily stores results of calculation executed by theprocessing section 31 according to various programs, and the like. Thestorage section 34 may store data which is required to be preserved fora long period of time among data items generated through processing ofthe processing section 31.

The communication section 32 performs data communication with thecommunication section 27 (refer to FIG. 9) of the swing analysisapparatus 20 via the network 40. For example, the communication section32 performs a process of receiving the swing analysis data 248 from thecommunication section 27 of the swing analysis apparatus 20, andtransmitting the swing analysis data 248 to the processing section 31.For example, the communication section 32 performs a process oftransmitting information required to display the selection screenillustrated in FIG. 7 to the communication section 27 of the swinganalysis apparatus 20, or a process of receiving selected information onthe selection screen illustrated in FIG. 7 from the communicationsection 27 of the swing analysis apparatus 20 and transmitting theselected information to the processing section 31. For example, thecommunication section 32 performs a process of receiving informationrequired to display the display screen illustrated in FIG. 8 from theprocessing section 31, and transmitting the information to thecommunication section 27 of the swing analysis apparatus 20.

The processing section 31 performs a process of receiving the swinganalysis data 248 from the swing analysis apparatus 20 via thecommunication section 32 and storing the swing analysis data 248 in thestorage section 34 (adding the swing analysis data to the swing analysisdata list 341), according to various programs. The processing section 31performs a process of receiving various pieces of information from theswing analysis apparatus 20 via the communication section 32, andtransmitting information required to display various screens (therespective screens illustrated in FIGS. 7 and 8) to the swing analysisapparatus 20, according to various programs. The processing section 31performs other various control processes.

Particularly, in the present embodiment, the processing section 31functions as a data acquisition portion 310 and a storage processingportion 312 by executing a predetermined program.

The data acquisition portion 310 performs a process of receiving theswing analysis data 248 received from the swing analysis apparatus 20 bythe communication section 32 and transmitting the swing analysis data248 to the storage processing portion 312.

The storage processing portion 312 performs read/write processes ofvarious programs or various data for the storage section 34. Forexample, the storage processing portion 312 performs a process ofreceiving the swing analysis data 248 from the data acquisition portion310 and storing the swing analysis data 248 in the storage section 34(adding the swing analysis data to the swing analysis data list 341), aprocess of reading the swing analysis data 248 from the swing analysisdata list 341 stored in the storage section 34, or the like.

1-5. Process in Server Apparatus

The processing section 31 of the server apparatus 30 transmits andreceives data to and from the swing analysis apparatus 20, and thusmanages user swing analysis data for each user.

Procedures of Process in Server Apparatus

FIG. 23 is a flowchart illustrating examples of procedures of a processperformed by the processing section 21 of the swing analysis apparatus20 in relation to a process in the server apparatus. FIG. 24 is aflowchart illustrating examples of procedures of a process in the serverapparatus. The processing section 31 (an example of a computer) of theserver apparatus 30 performs a process, for example, according to theprocedures of the flowchart of FIG. 24 by executing the program storedin the storage section 34. Hereinafter, the flowcharts of FIGS. 23 and24 will be described.

First, the processing section 21 of the swing analysis apparatus 20transmits user identification information allocated to the user 2, tothe server apparatus 30 (step S100 in FIG. 23).

Next, the processing section 31 of the server apparatus 30 receives theuser identification information, and transmits list information of theswing analysis data 248 corresponding to the user identificationinformation (step S200 in FIG. 24).

Next, the processing section 21 of the swing analysis apparatus 20receives the list information of the swing analysis data 248, anddisplays a selection screen (FIG. 7) of the swing analysis data on thedisplay section 25 (step S110 in FIG. 23).

The processing section 21 of the swing analysis apparatus 20 waits forthe swing analysis data 248 to be selected on the selection screen ofthe swing analysis data (N in step S120 in FIG. 23), and transmitsselected information of the swing analysis data to the server apparatus30 (step S130 in FIG. 23) if the information is selected (Y in step S120in FIG. 23).

Next, the processing section 31 of the server apparatus 30 receives theselected information of the swing analysis data (step S210 in FIG. 24).

Next, the processing section 31 of the server apparatus 30 transmits theselected swing analysis data (step S240 in FIG. 24).

Next, the processing section 21 of the swing analysis apparatus 20receives the selected swing analysis data, displays images (imagesindicating various indexes, an image indicating a swing trajectory, andthe like) based on the swing analysis data on the display section 25(step S140 in FIG. 23), and finishes the process.

In the flowchart of FIG. 23, order of the respective steps maybe changedas appropriate within an allowable range, some of the steps may beomitted or changed, and other steps maybe added thereto. Similarly, inthe flowchart of FIG. 24, order of the respective steps may be changedas appropriate within an allowable range, some of the steps may beomitted or changed, and other steps may be added thereto.

1-6. Standing-Still Determination in Swing Analysis Apparatus 1-6-1.Outline of Standing-Still Determination

As illustrated in FIG. 21, the swing analysis apparatus 20 of thepresent embodiment notifies the user 2 of permission of swing startingusing the golf club 3 (step S18) in a case where it is determined thatthe golf club 3 stands still (standing still state) (Y in step S16)after the measurement starting operation is performed (Y in step S10),and does not notify the user 2 of permission of swing starting in a casewhere the golf club 3 does not stand still (N in step S16).Specifically, in a case where an attitude of the golf club 3 isunstable, or an attitude of the golf club 3 is considerably deviatedrelative to a standard address attitude, the swing analysis apparatus 20of the present embodiment does not notify the user 2 of permission ofswing starting.

However, even in a case where the user 2 takes an address attitude andstands still, the user 2 is not notified of permission of swingstarting. Causes thereof may be considered to be the following cause (1)or cause (2).

(1) A swing analysis application installed in the swing analysisapparatus 20 or the sensor unit 10 fails.

(2) The user 2 stands still at an accurate address attitude, but thegolf club 3 does not satisfy a condition for being determined asstanding still by the swing analysis apparatus 20.

Of the causes, in a case of the cause (1), the sensor unit 10 isrequired to be repaired or the swing analysis application is required tobe repaired (reinstalled or the like), but, in a case of the cause (2),repair is not necessary, and the user 2 has only to adjust an addressattitude.

However, it is hard for the user 2 to determine which one of the causes(1) and (2) is a real cause. Thus, a problem occurs in that the user 2requests a manufacturer of the sensor unit 10 or a provider (forexample, a manager of the server apparatus 30) of a swing analysisapplication to repair the sensor unit 10 despite a cause being the cause(2), or the user 2 spends time in trying to improve an address attitudemany times despite a cause being the cause (1).

Therefore, the swing analysis apparatus 20 of the present embodimentnotifies the user 2 of a state of the golf club 3 in real time duringexecution of the process in step S16 in FIG. 21, that is, duringexecution of a process for determining whether or not the golf club 3stands still at an accurate attitude for a predetermined period of time(hereinafter, this process will be referred to as a “standing-stilldetermination”).

Therefore, the user 2 variously changes a state of the golf club 3 whilechecking the content of a notification during a standing-stilldetermination (step S16 in FIG. 21), and can thus experience that swingstarting is permitted in a case where what state a state of the golfclub 3 becomes. The user 2 having such an experience can accuratelyunderstand an address attitude to be taken in order for swing startingto be permitted.

In a case where there is no change in the content of a notificationdespite the user 2 variously changing a state of the golf club 3 duringthe standing-still determination (step S16 in FIG. 21), the user 2 canimmediately determine that the sensor unit 10 or the swing analysisapplication fails.

1-6-2. Fundamental Process in Standing-Still Determination

First, a description will be made of a fundamental process in thestanding-still determination (step S16 in FIG. 21).

Fundamentally, it is assumed that the swing analysis portion 211 of theswing analysis apparatus 20 of the present embodiment determines thatthe golf club 3 stands still (at an accurate attitude) in a case where astate (an example of a predetermined state) in which both of thefollowing standing-still condition (A) and attitude condition (B) aresatisfied lasts for a predetermined period of time (for example, aperiod of time of 2 seconds; an example of a determination criterion).For example, here, it is assumed that standing still is determined in acase where both of the standing-still condition (A) and the attitudecondition (B) are satisfied, but standing still may be determined in acase where one of the conditions is satisfied.

(A) A change amount of an attitude of the shaft per unit time, indicatedby three-axis angular velocity data, is less than a threshold value (anexample of a determination criterion). In order to determine whether ornot the standing-still condition (A) is satisfied, the swing analysisportion 211 computes an attitude change amount per 1 ms on the basis ofangular velocity data (or acceleration data) measured in a predeterminedcycle (for example, 1 ms), and determines whether or not the attitudechange amount is less than a predetermined threshold value. The swinganalysis portion 211 repeatedly performs this determination, forexample, in a predetermined cycle (for example, 1 ms).

(B) An inclined angle α (hereinafter, referred to as a shaft angle α ina hands-up direction) of the shaft in a lie angle direction, indicatedby three-axis acceleration data is included in a standard range (anexample of a determination criterion). In order to determine whether ornot the attitude condition (B) is satisfied, for example, the swinganalysis portion 211 computes a shaft angle α in a hands-up direction(an example of a direction intersecting a grounding plane) on the basisof acceleration data (a y-axis acceleration component a_(y) and a z-axisacceleration component a_(z)) measured in a predetermined cycle (forexample, 1 ms), and determines whether or not the shaft angle α in thehands-up direction is included in the standard range. The swing analysisportion 211 repeatedly performs this determination, for example, in apredetermined cycle (for example, 1 ms).

The shaft angle α in the hands-up direction is an angle indicated by thereference sign a in FIG. 10, and is an angle formed between the shaft (yaxis) and the Y axis in the YZ plane.

The shaft angle α in the hands-up direction is an angle formed betweenthe extending direction (y axis) of the shaft and the ground surface(horizontal plane) in the yz plane as illustrated in FIG. 10. The shaftangle α in the hands-up direction is expressed by the z-axisacceleration component a_(z) and the y-axis acceleration component a_(y)included in the three-axis acceleration data. For example, the swinganalysis portion 211 regards that the shaft angle α in the hands-updirection is increased as the ratio (a_(y)/a_(z)) between the z-axisacceleration component a_(z) and the y-axis acceleration component a_(y)becomes higher.

The standard range of the shaft angle α in the hands-up direction is arange of the shaft angle α in the hands-up direction centering on a lieangle α_(Lie) specific to the golf club 3, and is expressed by(α_(Lie)−Δα)<α<(α_(Lie)+Δα). The width (2Δα) of the standard range isset to be equivalent to, for example, a difference between shaft anglesα in the hands-up direction of various users 2 at address using the golfclubs 3 of the same type.

The lie angle α_(Lie) specific to the golf club 3 corresponds to a shaftangle α in the hands-up direction when a sole surface of the head of thegolf club 3 is brought into contact with the ground at an attitude ofbeing along the ground surface (horizontal plane).

Information regarding the lie angle α_(Lie) specific to the golf club 3is assumed to be included in the golf club information 242 which isinput to the swing analysis apparatus 20 in advance by the user 2.Therefore, the swing analysis portion 211 can recognize the lie angleα_(Lie) specific to the golf club 3 on the basis of the golf clubinformation 242.

1-6-3. Notification during Standing-Still Determination

Next, a description will be made of a notification during thestanding-still determination (step S16 in FIG. 21).

Here, a description will be made of a case where a notification duringthe standing-still determination (a period until reaching adetermination of a standing still state) is a notification using animage (indicator screen), but, not only a notification using an imagebut also a notification using a sound, a notification using vibration, anotification using a light luminance change pattern, a notificationusing a color change pattern, a notification using a sound changepattern, and a notification using a vibration change pattern may beemployed, and a notification using a combination of two or morenotifications may be employed.

A notification using an image or light is performed by, for example, theprocessing section 21 (particularly, the display processing portion 214)and the display section 25, and a notification using a sound isperformed by the processing section 21 (particularly, the sound outputprocessing portion 215) and the sound output section 26. A notificationusing vibration is performed by, for example, the processing section 21(particularly, a vibration output processing portion (not illustrated)),and a vibration mechanism (not illustrated). However, hereinafter, adescription will be made assuming that the processing section 21performs a notification alone.

First, the processing section 21 sequentially reflects shaft angles α inthe hands-up direction, computed during the standing-stilldetermination, on an indicator screen (which will be described later) ofthe display section 25. Consequently, when viewed from the user 2, theshaft angle α in the hands-up direction is displayed on an indicatorscreen (which will be described later) nearly in real time.Consequently, a change (state change) between the shaft angles α in thehands-up direction is displayed.

The processing section 21 reflects an x-axis acceleration componenta_(x) of acceleration data measured in a predetermined cycle (forexample, 1 ms) during the standing-still determination, on indicatorscreens (FIGS. 25 to 28 which will be described later). The x-axisacceleration component a_(x) indicates the extent of an inclined angle γ(hereinafter, referred to as a shaft angle γ in a hand-first direction)in a loft angle direction (an example of a horizontal direction withrespect to the ground plane) of the shaft.

The shaft angle γ in the hand-first direction is an angle formed betweenthe shaft (y axis) and the Z axis in the XZ plane.

Assuming that an attachment attitude of the sensor unit 10 with respectto the golf club 3 is as illustrated in FIG. 3, it may be regarded thatthe shaft angle γ in the hand-first direction increases as the x-axisacceleration component a_(x) increases.

Therefore, when viewed from the user 2, the extent of the shaft angle γin the hand-first direction is displayed on an indicator screen nearlyin real time. Consequently, a change (state change) between shaft anglesy in the hand-first direction is displayed.

The processing section 21 displays a standard range((α_(Lie)−Δα)<α<(α_(Lie)+Δα)) of the shaft angle α in the hands-updirection during the standing-still determination. Therefore, the user 2can understand an approximate target of the shaft angle α in thehands-up direction along with an actual shaft angle α in the hands-updirection.

FIG. 25 illustrates an example of an indicator screen.

As illustrated in FIG. 25, a text image 25C with the content that “bringthe head contact with the ground in a case of large shaking” is disposedto prompt the user 2 to stand still on an indicator screen. A text imagewith the content that “standstill” for instructing the user 2 to take anaddress attitude may be disposed on the indicator screen.

A pointer 25A (an example of information indicating a state change ofthe exercise equipment) is disposed on the indicator screen. A positionof the pointer 25A on the indicator screen indicates the presentattitude of the golf club 3 with respect to the horizontal plane.

First, a vertical position of the pointer 25A on the indicator screenindicates the shaft angle α in the hands-up direction (an example of anattitude change in a direction intersecting the ground surface). Thepointer 25A is located further toward an upper side as the shaft angle αin the hands-up direction increases, and the pointer 25A is locatedfurther toward a lower side as the shaft angle α in the hands-updirection decreases.

A horizontal position of the pointer 25A on the indicator screenindicates the shaft angle γ in the hand-first direction (an example ofan attitude change in the horizontal direction with respect to theground surface). The pointer 25A is located further toward the left asthe shaft angle γ in the hand-first direction increases, and the pointer25A is located further toward the right as the shaft angle γ in thehand-first direction decreases.

On the indicator screen illustrated in FIG. 25, a standard range of theshaft angle α in the hands-up direction is indicated by a pair of linearmarks 25B. Of the pair of linear marks 25B, the linear mark 25B locatedon the upper side in the indicator screen indicates an upper limit ofthe standard range, and the linear mark 25B located on the lower side inthe indicator screen indicates a lower limit of the standard range.

A temporal change of a position of the pointer 25A on the indicatorscreen represents a temporal change of an attitude of the golf club 3.Specifically, a temporal change of a position of the pointer 25A in thevertical direction represents a temporal change of the shaft angle α inthe hands-up direction, and a temporal change of a position of thepointer 25A in the horizontal direction represents a temporal change ofthe shaft angle γ in the hand-first direction.

Therefore, the user 2 takes an address attitude so that the pointer 25Aenters a rectangular region interposed between the pair of linear marks25B, and a position of the pointer 25A is stabilized, and maintains thestate for two seconds so that the swing analysis apparatus 20 canrecognize that the golf club 3 stands still at an accurate attitude.

The user 2 may understand a hand-first amount at the address attitudethereof on the basis of a position of the pointer 25A in the horizontaldirection. For example, it may be recognized that a hand-first amountbecomes larger as the pointer 25A is located further toward the left.

FIG. 26 illustrates another example of an indicator screen. Here, adifference from the indicator screen illustrated in FIG. 25 will befocused.

In an indicator screen illustrated in FIG. 26, the standard range of theshaft angle α in the hands-up direction is indicated by a pair ofarrowhead marks 25B′.

Directions of the pair of arrowhead marks 25B′ are set to directions inwhich tip ends thereof face each other. Of the pair of arrowhead marks25B′, the arrowhead mark 25B′ located on the upper side in the indicatorscreen indicates an upper limit of the standard range, and the arrowheadmark 25B′ located on the lower side in the indicator screen indicates alower limit of the standard range.

Therefore, the user 2 takes an address attitude so that the pointer 25Aenters a region interposed between the pair of arrowhead marks 25B′, anda position of the pointer 25A is stabilized, and maintains the state fortwo seconds so that the swing analysis apparatus 20 can recognize thatthe golf club 3 stands still at an accurate attitude.

FIG. 27 illustrates still another example of an indicator screen. Here,a difference from the indicator screen illustrated in FIG. 26 will befocused.

In an indicator screen illustrated in FIG. 27, the standard range of theshaft angle α in the hands-up direction is indicated by a pair ofpartial annular belt-shaped marks 25B″.

Directions of the pair of partial annular belt-shaped marks 25B″ are setto directions in which recessed parts thereof face each other. Of thepair of partial annular belt-shaped marks 25B″, the partial annularbelt-shaped marks 25B″ located on the upper side in the indicator screenindicate an upper limit of the standard range, and the partial annularbelt-shaped marks 25B″ located on the lower side in the indicator screenindicate a lower limit of the standard range.

A width of the pair of partial annular belt-shaped marks 25B″ in thehorizontal direction is set to a size corresponding to a standard range(which will be described later) of the shaft angle γ in the hand-firstdirection.

The indicator screen illustrated in FIG. 27 auxiliarily displays a pairof arrowhead marks 25B′ indicating the standard range of the shaft angleα in the hands-up direction. The pair of arrowhead marks 25B′ is thesame as the arrowhead marks 25B′ illustrated in FIG. 26.

Therefore, the user 2 takes an address attitude so that the pointer 25Aenters an elliptical or circular region interposed between the pair ofpartial annular belt-shaped marks 25B″, and a position of the pointer25A is stabilized, and maintains the state for two seconds so that theswing analysis apparatus 20 can recognize that the golf club 3 standsstill at an accurate attitude.

The user 2 takes an address attitude so that the pointer 25A enters thecenter of the elliptical or circular region interposed between the pairof partial annular belt-shaped marks 25B″, and thus the shaft angle α inthe hands-up direction can be made to match the lie angle α_(Lie), andthe shaft angle γ in the hand-first direction can be made to zero (ahand-first amount can be made to zero).

FIG. 28 illustrates still another example of an indicator screen. Here,a difference from the indicator screen illustrated in FIG. 27 will befocused.

The same pair of partial annular belt-shaped marks 25B″ as illustratedin FIG. 27, the same pair of arrowhead marks 25B′ as illustrated in FIG.27, and another pair of arrowhead marks 25D not illustrated in FIG. 27are disposed on an indicator screen illustrated in FIG. 28.

Another pair of arrowhead marks 25D indicates a standard range (whichwill be described later) of the shaft angle γ in the hand-firstdirection. Of the pair of arrowhead marks 25D, the arrowhead mark 25Dlocated on the left side in the indicator screen indicates an upperlimit of the standard range (which will be described later), and thearrowhead mark 25D located on the right side in the indicator screenindicates a lower limit of the standard range (which will be describedlater).

In the example illustrated in FIG. 28, a cross mark indicating thecenter of the standard range of the shaft angle α in the hands-updirection and the center of the standard range (which will be describedlater) of the shaft angle γ in the hand-first direction is displayed.

The user 2 takes an address attitude so that the pointer 25A enters thecenter of the cross mark, and thus the shaft angle α in the hands-updirection can be made to match the lie angle α_(Lie), and the shaftangle γ in the hand-first direction can be made to zero (a hand-firstamount can be made to zero).

1-6-4. Analysis Process (Calibration) after Standing-Still Determination

Here, the analysis process after the standing-still determination (stepS22 in FIG. 21) will be described in detail.

If impact is detected (Y in step S20 in FIG. 21) after thestanding-still determination (step S16 in FIG. 21), the processingsection 21 extracts measured data during a swing before and after theimpact, from measured data generated by the sensor unit 10.

For example, the processing section 21 detects respective timings ofswing starting, a top, impact, and the like on the basis of the measureddata generated by the sensor unit 10 before and after the impact, andextracts, for example, measured data generated in a period from swingstarting to impact as the measured data during the swing.

The processing section 21 performs bias correction on the measured dataduring the swing and setting of global coordinates (setting of a targetdirection) by referring to measured data for two seconds for which thegolf club 3 stands still at an accurate attitude before starting aswing, on the basis of the measured data generated by the sensor unit 10before and after the impact.

The processing section 21 generates swing analysis data includingvarious indexes and trajectories regarding the swing on the basis of themeasured data during the swing. The various indexes are calculatedaccording to the above-described methods. The indexes and thetrajectories are expressed by using global coordinates.

1-6-5. Process of Standing-Still Determination

Here, the step (step S16 in FIG. 21) regarding the standing-stilldetermination will be described in detail.

FIG. 29 is a flowchart illustrating examples of procedures of a swinganalysis process (an example of a determination method) performed by theprocessing section 21. FIG. 29 is a flowchart in which step S16 (anexample of a determination step) regarding the standing-stilldetermination is subdivided into a plurality of steps S161 to S166 inthe flow illustrated in FIG. 21.

Hereinafter, respective steps illustrated in FIG. 29 will be described.In FIG. 29, the same steps as the steps in FIG. 21 are given the samereference numerals.

Step S10: The processing section 21 determines whether or not ameasurement starting operation is performed by the user 2 (step S10),proceeds to a starting process (step S12) if the measurement startingoperation is performed (Y in step S10), and continuously displays theinitial screen if otherwise (N in step S10).

Step S12: The processing section 21 transmits a measurement startingcommand to the sensor unit 10, and starts to acquire measured data fromthe sensor unit 10 (step S12).

Step S14: The processing section 21 instructs the user 2 to take anaddress attitude (step S14).

Step S161: The processing section 21 computes an attitude change amountper unit time, an shaft angle α in the hands-up direction, and an shaftangle γ in the hand-first direction (step S161).

Step S162: The processing section 21 computes a standard range of theshaft angle α in the hands-up direction, and displays the range on anindicator screen along with a pointer (step S162). In a case where astandard range of the shaft angle γ in the hand-first direction isdisplayed on the indicator screen, the processing section 21 computesand displays the standard range in this step.

Step S163: The processing section 21 reflects the shaft angle α in thehands-up direction and the shaft angle γ in the hand-first direction ina position of the pointer on the indicator screen (step S163). Step S163is an example of a notification step.

Step S164: The processing section 21 determines whether or not thecomputed attitude change amount is less than a predetermined thresholdvalue (step S164), proceeds to an attitude determination (step S165) ifthe attitude change amount is less than the threshold value (Y in stepS164), and skips the attitude determination and proceeds to ameasurement finishing determination (step S24) if otherwise (N in stepS164).

Step S165: The processing section 21 determines whether or not thecomputed shaft angle α in the hands-up direction is included in thestandard range (step S165), proceeds to a time determination (step S166)if the shaft angle α in the hands-up direction is included in thestandard range (Y in step S165), and skips the time determination andproceeds to the measurement finishing determination (step S24) ifotherwise (N in step S165).

Step S166: The processing section 21 determines whether or not a periodof time for which the shaft angle αin the hands-up direction is includedin the standard range reaches a predetermined period of time (forexample, two seconds) (step S166) when the attitude change amount isless than the threshold value, proceeds to a swing permission process(step S18) if the period of time reaches the predetermined period oftime (Y in step S166), and proceeds to the measurement finishingdetermination (step S24) if otherwise (N in step S166).

Step S18: The processing section 21 notifies the user 2 of permission ofswing starting (step S18). Step S18 is an example of a notificationstep.

Step S20: The processing section 21 determines whether or not impact isdetected within a predetermined period from the permission of the swing(step S18) on the basis of the measured data acquired from the sensorunit 10 (step S20), proceeds to a swing analysis data generation process(step S22) if the impact is detected (Y in step S20), and proceeds tothe finish determination process (step S24) if otherwise (N in stepS20).

Step S22: The processing section 21 extracts measured data during theswing before and after the impact, from the measured data acquired fromthe sensor unit 10, calculates various indexes and trajectories on thebasis of the measured data during the swing, generates swing analysisdata including the indexes and the trajectories, and transmits the swinganalysis data to the server apparatus 30 (step S22). The processingsection 21 uses the measured data in the period in which the golf club 3stands still at an accurate attitude, for performing bias correction onthe measured data during the swing and setting of global coordinates.The processing section 21 uses parameters appropriate for the type(specification) of golf club 3 which is being designated at the presentpoint in order to calculate the indexes and the trajectories. Theprocessing section 21 may cause the measured data itself (so-called rawdata) during the swing to be included or information regarding thecurrently designated type of golf club 3 in the swing analysis datawhich is transmitted to the server apparatus 30.

Step S24: The processing section 21 determines whether or not ameasurement finishing operation has been performed by the user 2 (stepS24), finishes the flow if the operation has been performed (Y in stepS24), and proceeds to the address instruction process (step S14) ifotherwise (N in step S24).

In the flowchart of FIG. 29, order of the respective steps maybe changedas appropriate within an allowable range, some of the steps may beomitted or changed, and other steps may be added thereto.

1-7. Operations and Effects

As described above, since the swing analysis apparatus 20 of the presentembodiment (an example of an electronic apparatus) notifies the user 2of an attitude change (an example of a state change) of the golf club 3(an example of an exercise equipment) during a determination (untilreaching a determination), the user 2 can compare an attitude change ofthe golf club 3 when preset determination criteria (here, a thresholdvalue of an attitude change amount, a standard range of an angle α, anda period of two seconds; in the present embodiment, the standing-stillcondition and the attitude condition are satisfied for a predeterminedperiod of time) are not satisfied with an attitude change of the golfclub 3 when the determination criteria are satisfied. Therefore, theuser 2 variously changes a state of the golf club 3 while checking thecontent of a notification during a determination, and can thusexperience that swing starting is permitted (an example of apredetermined determination result) in a case where what state a stateof the golf club 3 becomes. As a result, the user 2 can accuratelyunderstand an address attitude (an example of the way of handling thegolf club 3) to be taken in order for swing starting to be permitted. Inother words, it is possible to comfortably use a function of determininga state of exercise equipment.

2. MODIFICATION EXAMPLES

The invention is not limited to the present embodiment, and may bevariously modified within the scope of the spirit of the invention.

2-1. Attitude Condition

In the present embodiment, conditions for determining that the golf club3 stands still at an accurate attitude are two conditions such as thestanding-still condition (A) and the attitude condition (B) (steps S164and S165 in FIG. 29), but the following attitude condition (C) may beadded thereto.

(C) A shaft angle γ in the hand-first direction, indicated by three-axisacceleration data, is included in a standard range. In order todetermine whether or not the attitude condition (C) is satisfied, forexample, the processing section 21 computes a shaft angle γ in thehand-first direction on the basis of acceleration data (x-axisacceleration component a_(x)) measured in a predetermined cycle (forexample, 1 ms), and determines whether or not the shaft angle γ in thehand-first direction is included in a standard range. Consequently, itis determined whether or not the shaft angle γ in the hand-firstdirection is included in the standard range. The processing section 21repeatedly performs this determination, for example, in a predeterminedcycle (for example, 1 ms).

The shaft angle γ in the hand-first direction is an angle formed betweenthe extending direction (y axis) of the shaft and the ground surface(horizontal plane) in the XZ plane. The shaft angle γ in the hand-firstdirection is expressed by the x-axis acceleration component a_(x)included in three-axis acceleration data. For example, the processingsection 21 regards the shaft angle γ in the hand-first direction to bezero if the x-axis acceleration component a_(x) is zero, and regardsthat the shaft angle γ in the hand-first direction increases as thex-axis acceleration component a_(x) increases.

The standard range of the shaft angle γ in the hand-first direction isset to a range centering on, for example, zero. A width of the standardrange is set to a width corresponding to a difference between shaftangles y in the hand-first direction at address of various users 2 usingthe golf club 3 of the same type.

In this case, as an indicator screen, the indicator screen illustratedin FIG. 27 or 28 may be employed.

2-2. Adjustment of Indicator Screen

In the above-described embodiment, the processing section 21 uses theindicator screen in order to notify the user 2 of an attitude of thegolf club 3 during a standing-still determination, but may allow theuser 2 to adjust a display size of the indicator screen (at least theregion surrounded by the image indicating the standard range) in orderfor the indicator screen to be easily viewed, and may allow the user 2to adjust an aspect ratio of the indicator screen (at least the regionsurrounded by the image indicating the standard range).

In the above-described embodiment, in a case where the swing analysisapparatus 20 is leaned against a wall or the like, or an image from theswing analysis apparatus 20 is projected onto a wall or the like, theprocessing section 21 may allow the user 2 to adjust a ratio(trapezoidal distortion) between a width of an upper end and a width ofa lower end of the indicator screen in order for the user 2 to easilyview the indicator screen.

2-3. Modifications of Indicator Screen

In the above-described embodiment, the processing section 21 may changeat least one of a color, luminance, a grayscale, texture, a paint-outpattern, and the like of the pointer 25A depending on at least one of afrequency and the amplitude of an attitude change of the golf club 3. Afrequency of an attitude change or the amplitude of an attitude changemay be obtained on the basis of angular velocity data or accelerationdata.

In the above-described embodiment, the processing section 21 may displayscales for indicating a criterion of an attitude of the golf club 3 onthe indicator screen. In the indicator screens illustrated in FIGS. 25,27 and 28, scales are added to the linear marks 25B or the partialannular belt-shaped marks 25B″ indicating the standard range.

In the above-described embodiment, the processing section 21 maysequentially draw movement trajectories of the pointer during thestanding-still determination on the indicator screen. If thetrajectories are drawn, the user 2 can recognize in which range anattitude thereof is unstable.

In the above-described embodiment, the processing section 21 may useother images (for example, an indicator image) instead of the pointer25A as an image indicating an attitude or the like of the golf club 3during the standing-still determination. For example, the processingsection 21 in the above-described embodiment may use various realindicator images such as an image of a level, or an image of an analogtype attitude indicator as the indicator screen.

In the above-described embodiment, the processing section 21 displaysthe partial annular belt-shaped marks 25B″ in order to indicate thestandard range on the indicator screens illustrated in FIGS. 27 and 28,and may use annular belt-shaped marks in order to indicate the standardrange.

2-4. Notification Off

In the above-described embodiment, the swing analysis apparatus 20 mayallow the user 2 to turn off the function (indicator screen) ofnotifying the user 2 of an attitude of the golf club 3 during thestanding-still determination.

The swing analysis apparatus 20 in the above-described embodiment mayhave the notification function (indicator screen) as one of practicemodes.

In the above-described embodiment, in a case where the notificationfunction (indicator screen) is turned off, the processing section 21 mayturn on other functions, for example, a video capturing function,instead of the notification function (indicator screen). The videocapturing function is a function of capturing a video of a state of theuser 2 at an address attitude or during a swing, and displaying capturedvideo images on the display section 25 in real time. The video capturingis performed by an imaging section (camera) mounted in the swinganalysis apparatus 20.

2-5. Other Notification Aspects

In the above-described embodiment, the processing section 21 may usevarious aspects as an aspect of notifying the user 2 of an attitude orthe like of the golf club 3 during a standing-still determination. As anotification aspect, for example, at least one of an image, light,sound, vibration, an image change pattern, a light change pattern, asound change pattern, and a vibration change pattern may be used.

For example, in the above-described embodiment, the processing section21 may provide a difference to each combination of images, light beams,sounds, vibration items, image change patterns, light change patterns,sound change patterns, and vibration change patterns between cases wherean inclined angle is included in a standard range and is deviated fromthe standard range.

For example, in the above-described embodiment, the processing section21 may provide a difference to each combination of images, light beams,sounds, vibration items, image change patterns, light change patterns,sound change patterns, and vibration change patterns between cases wherean attitude change amount per unit time is less than a threshold valueand is equal to or more than the threshold value.

For example, in the above-described embodiment, the processing section21 may generate a warning sound (uncomfortable sound) in a case where aninclined angle is deviated from a standard range, and may generate awarning cancel sound (comfortable sound) in a case where an inclinedangle is included in the standard range.

For example, in the above-described embodiment, the processing section21 may generate a warning sound (uncomfortable sound) in a case where anattitude change amount per unit time is deviated from a standard range,and may generate a warning cancel sound (comfortable sound) in a casewhere an attitude change amount per unit time is included in thestandard range.

For example, in the above-described embodiment, the processing section21 may cause the entire screen to blink in a warning color (yellow) in acase where an inclined angle is deviated from a standard range, and maycause the entire screen to continuously blink in a warning cancel color(blue) in a case where an inclined angle is included in the standardrange.

For example, in the above-described embodiment, the processing section21 may cause the entire screen to blink in a warning color (yellow) in acase where an attitude change amount per unit time is deviated from astandard range, and may cause the entire screen to continuously blink ina warning cancel color (blue) in a case where an attitude change amountper unit time is included in the standard range.

In the above-described embodiment, the processing section 21 may providea difference to each combination of images, light beams, sounds,vibration items, image change patterns, light change patterns, soundchange patterns, and vibration change patterns between cases where aninclined angle approaches to the center of a standard range and isseparated from the center of the standard range.

For example, in the above-described embodiment, the processing section21 may provide a difference to each combination of images, light beams,sounds, vibration items, image change patterns, light change patterns,sound change patterns, and vibration change patterns between cases wherean attitude change amount per unit time decreases and increases.

2-6. Standing-Still Determination Based on Angular Velocity Data

In the above-described embodiment, the processing section 21 calculatesan attitude of the golf club 3 to be reflected on the indicator screenon the basis of acceleration data, but may calculate an attitude of thegolf club 3 on the basis of both of angular velocity data andacceleration data.

In the above-described embodiment, the processing section 21 performs astanding-still determination for the golf club 3 on the basis of both ofangular velocity data and acceleration data, but may perform astanding-still determination on the basis of one of angular velocitydata and acceleration data. An example of an apparatus performing astanding-still determination based on angular velocity data is asfollows.

The apparatus includes a threshold value determination portion thatdetermines whether or not an angular velocity detected in a periodhaving a time length is included in a predetermined threshold valuerange on a time axis of a detection result from an angular velocitysensor detecting the angular velocity of a golf club; a bias valuesetting portion that sets a bias value included in the angular velocityon the basis of a first average value which is an average value of theangular velocity detected in the period in a case where the angularvelocity detected in the period is included in the threshold valuerange; and an analysis information calculation portion that analyzesmotion of the golf club on the basis of correction data from which thebias value is removed.

The threshold value determination portion may determine whether or notthe angular velocity is included in the threshold value range by using,as a reference, a second average value which is an average value of theangular velocity in all periods of the detection result.

In a case where there are a plurality of periods in which the angularvelocity is included in the threshold value range, the bias valuesetting portion may set the bias value on the basis of the first averagevalue in a period in which a difference between the second average valueand the angular velocity is smallest.

The threshold value determination portion may determine whether or not avariance value of the angular velocity detected in the period isincluded in the threshold value range.

In a case where there are a plurality of periods in which the variancevalue is included in the threshold value range, the bias value settingportion may set the bias value on the basis of the first average valuein a period in which the maximum variance value of the angular velocityis smallest.

At least one of the time length and the threshold value may be defineddepending on the type of motion of the golf club.

At least one of the time length and the threshold value may be defineddepending on a position where the angular velocity sensor is attached.

At least one of the time length and the threshold value may be defineddepending on a frequency component of a detection result from theangular velocity sensor.

2-7. Other Input Aspects

In the above-described embodiment, the processing section 21 mainlyinputs a single or a plurality of pieces of information from the user 2through touching of the finger (a tapping operation on a touch panel oran operation on a button), but various aspects may be used as an aspectof inputting a single or a plurality of pieces of information. As anaspect of inputting information, for example, at least one ofinformation input through touching of the finger, information inputusing a voice, and information input using gesture.

2-8. Modification of V Zone

In the above-described embodiment, the concept of the V zone (a regioninterposed between the shaft plane and the Hogan plane) is introduced inorder to define the regions A, B, C, D and E in which the head isincluded. The V zone is a region interposed between the first virtualplane along the longitudinal direction of the golf club 3 and the secondvirtual plane passing through the vicinity of the shoulder of the user2. The first virtual plane is, for example, a so-called shaft planespecified by a first axis along a target hit ball direction and a secondaxis along the longitudinal direction of the golf club 3 before a swingis started. The second virtual plane is, for example, a so-called Hoganplane which includes the first axis, and forms a predetermined anglewith the first virtual plane. However, the second virtual plane may be avirtual plane (including both of a virtual plane parallel to the firstvirtual plane and a virtual plane along the first virtual plane) whichis parallel to the first virtual plane. A parallel virtual plane may bereferred to as a “shoulder plane”. In the above-described embodiment,the second virtual plane may be calculated on the basis of both of thefirst virtual plane and physical information of the user 2, and a planehaving a predetermined relationship with the first virtual plane may bethe second virtual plane.

2-9. Modifications of Swing Analysis Process

For example, a plurality of sensor units 10 may be attached to the golfclub 3 or parts such as the arms or the shoulders of the user 2, and theswing analysis portion 211 may perform a swing analysis process by usingmeasured data from the plurality of sensor units 10.

In the embodiment, the swing analysis portion 211 calculates the thirdline segment 53 which is a third axis and the Hogan plane HP by usingthe physical information of the user 2, but a line segment and a planeobtained by rotating the second line segment 52 which is a second axisand the shaft plane SP by a predetermined first angle β (for example,30°) about the X axis, respectively, may be used as the third linesegment 53 and the Hogan plane HP.

In the embodiment, the swing analysis portion 211 detects impact byusing the square root of the square sum as shown in Equation (2) as acombined value of three-axis angular velocities measured by the sensorunit, but, as a combined value of three-axis angular velocities, forexample, a square sum of three-axis angular velocities, a sum or anaverage value of three-axis angular velocities, or the product ofthree-axis angular velocities may be used. Instead of a combined valueof three-axis angular velocities, a combined value of three-axisaccelerations such as a square sum or a square root of three-axisaccelerations, a sum or an average value of three-axis accelerations, orthe product of three-axis accelerations may be used.

2-10. Modification Examples such as HMD

In the above-described embodiment, as a display location of a single ora plurality of images, for example, a wrist type display section (anexample of a wrist mounted display device) as illustrated in FIG. 30 ora head mounted display section (hereinafter, referred to as an HMD; anexample of a head mounted display device) as illustrated in FIG. 31 maybe used.

The head mounted display is a display which is mounted on the head ofthe user 2, and displays an image with respect to one eye or both eyesof the user 2. The user 2 wearing the head mounted display on the headthereof can recognize various images without deviating a visual linethereof from the head of the golf club 3, a ball, or a target direction.

As illustrated in FIG. 31, an HMD 500 includes a spectacle main body 501mounted on the head of the user 2. The spectacle main body 501 isprovided with a display section 502. The display section 502 integratesa light beam emitted from an image display unit 503 with a light beamdirected toward the eyes of the user 2, and thus overlaps a virtualimage on the image display unit 503 with a real image of the externalworld viewed from the user 2.

The display section 502 is provided with, for example, the image displayunit 503 such as a liquid crystal display (LCD), a first beam splitter504, a second beam splitter 505, a first concave reflection mirror 506,a second concave reflection mirror 507, a shutter 508, and a convex lens509.

The first beam splitter 504 is disposed on the front side of the lefteye of the user 2, and partially transmits and partially reflects lightemitted from the image display unit 503.

The second beam splitter 505 is disposed on the front side of the righteye of the user 2, and partially transmits and partially reflects lightwhich is partially transmitted from the first beam splitter 504.

The first concave reflection mirror 506, which is disposed in front ofthe first beam splitter 504, partially reflects the partially reflectedlight from the first beam splitter 504 so as to transmit the lightthrough the first beam splitter 504, and thus guides the light to theleft eye of the user 2.

The second concave reflection mirror 507, which is disposed in front ofthe second beam splitter 505, partially reflects the partially reflectedlight from the second beam splitter 505 so as to transmit the lightthrough the second beam splitter 505, and thus guides the light to theright eye of the user 2.

The convex lens 509 guides partially transmitted light from the secondbeam splitter 505 to the outside of the HMD 500 when the shutter 508 isopened.

According to the HMD 500, the user 2 can understand necessaryinformation without holding the swing analysis apparatus 20 with thehands.

2-11. Others

In the above-described embodiment, some or all of the functions of thesensor unit 10 may be installed on the swing analysis apparatus 20 sideor the server apparatus 30 side. Some or all of the functions of theswing analysis apparatus 20 may be installed on the sensor unit 10 sideor the server apparatus 30 side. Some or all of the functions of theserver apparatus 30 may be installed on the swing analysis apparatus 20side or the sensor unit 10 side.

In the embodiment, the acceleration sensor 12 and the angular velocitysensor 14 are built into and are thus integrally formed as the sensorunit 10, but the acceleration sensor 12 and the angular velocity sensor14 may not be integrally formed. Alternatively, the acceleration sensor12 and the angular velocity sensor 14 may not be built into the sensorunit 10, and may be directly mounted on the golf club 3 or the user 2.In the above-described embodiment, the sensor unit 10 and the swinganalysis apparatus 20 are separately provided, but may be integrallyformed so as to be attached to the golf club 3 or the user 2. The sensorunit 10 may have some of the constituent elements of the swing analysisapparatus 20 along with the inertial sensor (for example, theacceleration sensor 12 or the angular velocity sensor 14).

The inertial sensor maybe a sensor which can measure an inertial amountsuch as acceleration or angular velocity, and may be, for example, aninertial measurement unit (IMU) which can measure acceleration orangular velocity. For example, the inertial sensor may be attached toexercise equipment or a part of a user so as to be attachable to anddetachable from the exercise equipment or the user, and may be fixed tothe exercise equipment so as to not be detached therefrom as a result ofbeing built into the exercise equipment.

In the above-described embodiment, the swing analysis system (serverapparatus) analyzing a golf swing has been exemplified, but theinvention is applicable to a swing analysis system (server apparatus)analyzing a swing in various sports such as tennis or baseball.

The above-described embodiment and modification examples are onlyexamples, and the invention is not limited thereto. For example, theembodiment and the respective modification examples may be combined witheach other as appropriate.

For example, the invention includes substantially the same configuration(for example, a configuration in which functions, methods, and resultsare the same, or a configuration in which objects and effects are thesame) as the configuration described in the embodiment. The inventionincludes a configuration in which an in essential part of theconfiguration described in the embodiment is replaced with another part.The invention includes a configuration which achieves the same operationand effect or a configuration capable of achieving the same object as inthe configuration described in the embodiment. The invention includes aconfiguration in which a well-known technique is added to theconfiguration described in the embodiment.

The entire disclosure of Japanese Patent Application No. 2016-005807filed Jan. 15, 2016 is expressly incorporated by reference herein.

What is claimed is:
 1. An electronic apparatus comprising: adetermination section that performs a determination of a standing stillstate of an exercise equipment by using an output from an inertialsensor; and a notification section that notifies a user of informationindicating an attitude change of the exercise equipment until reachingthe determination.
 2. The electronic apparatus according to claim 1,wherein the notification section notifies the user of permission ofstarting of a swing of the exercise equipment in a case where theexercise equipment is maintained in a predetermined state for apredetermined period of time.
 3. The electronic apparatus according toclaim 1, wherein the exercise equipment is a golf club, and wherein thenotification section notifies the user of an attitude change of the golfclub in a direction intersecting a ground plane as the information. 4.The electronic apparatus according to claim 1, wherein the exerciseequipment is a golf club, and wherein the notification section notifiesthe user of an attitude change of the golf club in a horizontaldirection with respect to a ground plane as the information.
 5. Theelectronic apparatus according to claim 1, wherein the exerciseequipment is a golf club, and wherein a criterion of the determinationis set on the basis of a lie angle of the golf club.
 6. The electronicapparatus according to claim 1, wherein the notification sectionnotifies the user of the criterion of the determination along with theinformation.
 7. The electronic apparatus according to claim 1, whereinthe notification section performs the notification by using at least oneof an image, light, sound, vibration, an image change pattern, a lightchange pattern, a sound change pattern, and a vibration change pattern.8. The electronic apparatus according to claim 1, wherein the inertialsensor includes at least one of an acceleration sensor and an angularvelocity sensor.
 9. A system comprising: the electronic apparatusaccording to claim 1; and the inertial sensor.
 10. A system comprising:the electronic apparatus according to claim 1; and a head mounteddisplay that displays the information.
 11. A system comprising: theelectronic apparatus according to claim 1; and an arm mounted displaythat displays the information.
 12. A determination method comprising:performing a determination of a standing still state of an exerciseequipment by using an output from an inertial sensor; and notifying auser of information indicating an attitude change of the exerciseequipment until reaching the determination.
 13. The determination methodaccording to claim 12, wherein, in the notifying of the information, theuser is notified of permission of starting of a swing of the exerciseequipment in a case where the exercise equipment is maintained in apredetermined state for a predetermined period of time.
 14. Thedetermination method according to claim 12, wherein the exerciseequipment is a golf club, and wherein, in the notifying of theinformation, the user is notified of an attitude change of the golf clubin a direction intersecting a ground plane as the information.
 15. Thedetermination method according to claim 12, wherein the exerciseequipment is a golf club, and wherein, in the notifying of theinformation, the user is notified of an attitude change of the golf clubin a horizontal direction with respect to a ground plane as theinformation.
 16. The determination method according to claim 12, whereinthe exercise equipment is a golf club, and wherein a criterion of thedetermination is set on the basis of a lie angle specific to the golfclub.
 17. The determination method according to claim 12, wherein, inthe notifying of the information, the user is notified of the criterionof the determination along with the information.
 18. The determinationmethod according to claim 12, wherein, in the notifying of theinformation, the notification is performed by using at least one of animage, light, sound, vibration, an image change pattern, a light changepattern, a sound change pattern, and a vibration change pattern.
 19. Thedetermination method according to claim 12, wherein the inertial sensorincludes at least one of an acceleration sensor and an angular velocitysensor.
 20. A recording medium recording a determination program causinga computer to execute: performing a determination of a state of anexercise equipment by using an output from an inertial sensor; andnotifying a user of information indicating an attitude change of theexercise equipment until reaching the determination.